Britain and the Protection of the Gulf During the Second World War: The Ad hoc Defence of a Peripheral Theatre

Introduction

In the years preceding the Second World War, the Arab shaikhdoms of Eastern Arabia – Kuwait, Bahrain, Qatar and the Trucial States (later the United Arab Emirates) ¹ – plus the body of water they front (i.e., the Gulf) ² had grown in importance to Britain, which had become by the beginning of the nineteenth century the undisputed power in the area. Despite the Gulf's steadily growing significance to British imperial strategy, Britain was, however, slow to develop a scheme of defence for the region should major war break out.

This article explains the reasons for Britain's lack of pre-war defensive preparations and describes the makeshift measures introduced in response to the Axis threat. At one level, London's wartime inattention to the Gulf is no puzzle: in contrast to more pressing concerns, not least defence of the home country, the area was peripheral to Britain. Moreover, Britain and its empire were militarily ill-prepared at war's outbreak. Scant available troops and military materiel were simply needed elsewhere. Despite these realities, British officials in the Gulf worked assiduously to convince their political and military superiors that the Gulf's fate was significant to Britain's wider East of Suez interests and that the threat to the area was underappreciated.

Drawing upon an extensive array of archival material, this article fills a notable gap in the historical coverage of the Second World War in the Middle East. While there is now a rich body of work on the war as it relates to Iraq (or Mesopotamia) and Iran (officially changed from Persia in 1935, but both names continued to be used interchangeably thereafter), very little has been written about the course of the war in the lower Gulf. ³ In step with efforts to examine the Second World War as a truly global phenomenon, ⁴ this article examines British military preparations towards the region and its wartime relations with the local rulers with whom Britain needed to cooperate and through whom Britain often had to work [or act]. It also serves to highlight the connections between the Gulf theatre and other crucial dimensions of the war effort, including shipping lanes traversing the Western Indian Ocean and the “Persian Corridor” for supplying the Soviet Union with military equipment.

In building up our multi-perspective narrative of the Second World War in Eastern Arabia and its adjacent waters, the article proceeds as follows. We first briefly describe the Gulf region's geographic and oil significance to Britain on the eve of war and the extent of British pre-war defence arrangements. The article then concentrates on the multi-domain threat to the wider Gulf region posed at different points from all three Axis powers – first Italy, then Germany and finally Japan. It explains how these emergent, and often surprising threats, along with the Gulf's growing importance as a logistics and communications node, challenged earlier planning assumptions and shaped British defence preparations. The final section, which forms the conclusion, reflects on the preceding analysis.

British Interests on the Eve of War

Throughout the first part of the nineteenth century, Britain's primary concern in the Gulf was the cessation of piracy and maritime warfare, both of which threatened mercantile shipping and London's lines of communication with India. ⁵ At the end of the nineteenth century and the beginning of the twentieth century, Britain also sought to exclude foreign powers from gaining a foothold in the area. It was during this time that the British government assumed full responsibility for the external relations of these shaikhdoms and that Britain conferred the status of ‘protected state’ upon them. Whilst Britain took responsibility for defence and external relations for the Arab shaikhdoms of Eastern Arabia under these special treaty arrangements, the local rulers retained sovereignty over internal affairs, except where these infringed on British interests. On land, Britain's military footprint was miniscule. ⁶ Britain maintained a small naval presence in the area headquartered in Bahrain, principally to secure the western maritime flank of British India and to protect trade. ⁷ This light touch approach to imperialism was in stark contrast to Britain's post-First World War presence elsewhere in the Middle East, including Mandatory Iraq at the head of the Gulf. ⁸

The discovery of oil in southern Iran and its exploitation by a British government-controlled company (the Anglo-Iranian Oil Company – AIOC) at the turn of the century transformed Britain's interests in the wider area. Persian oil became the chief source of fuel for the Royal Navy after it shifted from coal to oil. The need to protect the AIOC's refinery at Abadan – Britain's largest overseas investment at the time of its development – and the inland oil fields was recognised in the lead up to war. Indeed, the General Staff in India were instructed to maintain a ‘special scheme for sending a force to the area’ if it was threatened. ⁹ The British based much of their regional military presence in Iraq, also a valuable source of oil for Britain, piped from its northern fields to the Mediterranean via Syria and Palestine.

By the 1930s, the shaikhdoms and adjacent waters had emerged as a central node in Britain's critical east-west communications: the submarine telegraph cabling connecting Britain to India and onwards to the Far East and Australia passed through the Gulf; as did the ‘Imperial Air Route’, running through Habbaniya in Iraq, down to Bahrain, then to Sharjah, and thereafter across to Gwadar on the Indian subcontinent. Unlike the telegraph's declining importance due to the advent of wireless stations, the criticality of the Gulf leg of the air route burgeoned with the introduction of improved long-range aircraft and the ability to move more people and goods that came with this. Indeed, this section of the air route by now was referred to by British officials as the ‘Suez Canal of the Air’. ¹⁰

As war approached, Britain's attention to the protected Arab shaikhdoms was limited. This is not to say that British planners were disinterested in Eastern Arabia's fate. Nascent oil production in Bahrain from the early 1930s, the recognised potential for greater oil production elsewhere within the shaikhdoms and the landing sites for the east-west air link made the protected shaikhdoms all register in the minds of officials charged with formulating Britain's imperial strategy or crafting policy in the Middle East. Britain assumed, however, that the Gulf would be insulated from any significant attack on account of Britain holding its position in Egypt – the centrepiece of its Middle East policy – East Africa, the Levant, and Iraq.

Out of all the protected shaikhdoms, Bahrain was, on the eve of the war, in a class of its own. Although it would be several more years before Britain stationed its Gulf plenipotentiary – the Political Resident Persian Gulf (hereafter referred to as political resident) – to the tiny archipelago, Bahrain was already the cockpit of Britain's political, economic, and military presence in Eastern Arabia. By 1939 the American-managed oil company, Bahrain Petroleum Company (BAPCO), had drilled over a hundred wells. Oil produced went to a 10,000-barrels-per-day refinery on the main island. Although Bahrain's oil was too high in sulphur to be used by the Royal Navy, except in emergencies, it was suitable for commercial vessels and could be used for feedstock to produce a range of other oils and fuels at the refinery. ¹¹ While Bahraini oil production was dwarfed by that of Iran and Iraq, it nevertheless offered an alternative source of supply if production elsewhere was halted. ¹² Aside from oil, Bahrain's importance stemmed from basing the Royal Navy's Persian Gulf Squadron at HMS Jufair.

As already mentioned, Bahrain, along with the other shaikhdoms, served as important way stations along the east-west air link. In the 1930s the shaikhly rulers of Kuwait, Bahrain and the Trucial States (as well as the sultan in Muscat) agreed, in exchange for payments, to British air facilities on their territory. These consisted of aerodromes for land aircraft, and alighting areas for flying boats, supported by a network of emergency landing areas, fuel reserves and wireless stations with direction finding for air navigation. ¹³ As the Gulf was the most practical way to go eastabout, the route was worth protecting. If hostile action – such as seizing landing facilities or destroying wireless transmitting stations and fuel supplies – were to make the Gulf leg of the east-west air route unavailable, British aircraft would have to take a much more circuitous route to reach India and beyond. ¹⁴

Responsibility for protecting these British interests across the Gulf was shared across several British political and military entities located on different continents, each with their own perspective on the appropriate level of preparations for hostilities.

Pre-War Planning

Britain's political authority in the protected states was exercised by the political resident. Based for historical reasons at Bushire on the Iranian side of the coast, the political resident supervised a handful of political agents, political officers, and native agents across the shaikhdoms. The political resident and his British subordinates were part of the Indian Political Service and reported, via the External Affairs Department, to the Government of India. They also liaised with the India Office in London, which, headed by a secretary of state for India, was ultimately responsible for managing British India. Thus, British political interests in Eastern Arabia were seen largely through India Office eyes.

Responsibility for Britain's military position in the wider Gulf region, however, was split between the Air Ministry, the Admiralty, and the General Staff, India. Under the Air Ministry, the Royal Air Force headed the local inter-service command of British Forces in Iraq (renamed Air Headquarters Iraq (AHQ Iraq) in 1941). Headquartered before and during the war at Habbaniya west of Baghdad, the command was led by the Air Officer Commanding Iraq (AOC-Iraq), the principal British military officer in the Gulf region whose responsibility ostensibly extended to the Arab Gulf shaikhdoms.

Overlapping the RAF's area of responsibility, the Royal Navy's local command was vested in the Senior Naval Officer Persian Gulf (SNOPG) in Bahrain, who reported to the Commander-in-Chief, East Indies Station, headquartered in Trincomalee, Ceylon. The SNOPG commanded a squadron out of Bahrain which typically consisted of between two to four sloops (although due to refits, post changes and visits, often only one ship was available in the Gulf). Before the outbreak of war, these sloops represented the only permanent British military presence in Eastern Arabia. In addition to defending the waterways from foreign incursions, they had littoral responsibilities such as providing naval landing parties to protect British interests and putting on shows of force as part of both ‘gunboat diplomacy’ and reinforcing British prestige. To complete the picture, the General Staff, India held responsibility for protecting southern Iran's oil fields and certain ports, but it had no troops based in Iran to fulfil this role.

As the likelihood of war increased in the late 1930s, these various entities and their heads espoused different views about British interests in the region and the appropriate measures for its wartime defence. The political resident lamented that British authorities did not fully appreciate the growing strategic and oil importance of the shaikhdoms, particularly Bahrain. Starting in late 1937, he personally sought to elevate the importance of the protected shaikhdoms in both London and India and to concomitantly strengthen defence arrangements. Ideally, the political resident wanted this matter thrashed out within the Committee of Imperial Defence (CID). ¹⁵ In correspondence with the India Office, he was critical of the lack of resources available locally to mount an adequate defence. The political resident was under no illusion that few reinforcements would likely come from India in the event of major war. What is more, the sloops out of Bahrain, he predicted, would be patrolling the Strait of Hormuz to prevent entry of hostile vessels into the Gulf and would not be available for local defence of the Gulf ports and oil installations, which would be defenceless if a hostile cruiser or submarine with a large calibre gun ran the squadron's blockade.

Acknowledging the validity of some of the political resident's concerns, the India Office organised an interdepartmental meeting in London in April 1938 attended by the Air Ministry, Admiralty, and War Office. ¹⁶ The Admiralty and Air Ministry largely dismissed the threat to the Gulf; their officials certainly did not think it warranted repositioning resources. The Admiralty thought a hostile cruiser entering the Gulf or aircraft carrier operating in its vicinity was implausible and argued the local sloops were sufficient to deal with the most conceivable threats: submarines or raiders disguised as merchant ships. ¹⁷ In a similar vein, the Air Ministry believed an air attack was highly unlikely due to the long distances between the Gulf and any serious potential enemies. ¹⁸ The War Office officials made little contribution to the discussion, likely reflecting their lack of responsibility and interest in the area.

The General Staff India – which had no representatives at the meeting but later saw the meeting's conclusions – were less confident, believing that an air attack was conceivable against Bahrain from the 150-aircraft Iranian Air Force, as well as from seaborne aircraft or long-distance bombers from Italian Eritrea which was less than 1,000 miles from Bahrain. ¹⁹

But the political resident did not have in his mind only conventional threats. Drawing on his experience as a political officer in Mesopotamia during the First World War, he conceived that the coming war would see a repeat of many of the last war's practices: enemy agents sabotaging military supplies and vital facilities. ²⁰ Among the protected states, this meant the Bahraini oil fields and facilities and perhaps the air landing areas further down the coast in the Trucial States.

Formulating Early Defence Schemes

Responding to the political resident's jeremiads, the CID initiated in mid-1938 a formal assessment of Bahrain – the protected Arab shaikhdom most important to Britain. The committee requested that defence chiefs formally consider a plan for Bahrain, which it submitted in July 1938 as a three-page report entitled the Defence Scheme for Bahrain. The Chiefs of Staff concluded that while Bahrain held some importance due to its oil, it was less important than Rangoon or Trinidad. Furthermore, Bahrain's naval base held little military value, being principally for administration and recreation, and possessing no docking or repair facilities nor any significant naval stores or ammunition reserves. Lastly, while Bahrain had three air facilities – the civil Muharraq aerodrome, a Royal Air Force (RAF) airstrip near Manama, and the flying-boat landing area to the east of Manama (see ‘Pier’ at the RAF House in Fig. 1) – they could not in their present state support deployed RAF units. ²¹ Conceding that Bahrain's oil, naval and air facilities would likely become more important during a major conflict, British defence planners nevertheless ascribed Bahrain with little strategic value and largely dismissed it as a target for future enemy action. ²² Noting the Air Ministry would in time develop local defence schemes for the shaikhdoms, the Defence Scheme for Bahrain recommended no further action by the CID. ²³

OPEN IN VIEWER

Fig. 1.

1940 map of Bahrain with important points. ⁹³

Using the conclusions reached in the CID's Defence Scheme for Bahrain, the Air Ministry quashed the Government of India's concerns about the threat to Bahrain from air attack and refused to see the need to install coastal defences or anti-aircraft guns on Bahrain, or elsewhere in Gulf for that matter. ²⁴ The most credible threats raised in the report were sabotage by foreign agents or disgruntled employees and insecurity arising from tribal disputes; threats, the Air Ministry surmised, better handled by local security forces than British military units, which were, at any rate, needed elsewhere. ²⁵

Rather than wait for the AOC Iraq's local defence plans, the political resident tasked a subordinate, the political agent in Bahrain, Hugh Weightman, to develop and start implementing defence schemes for the shaikhdoms. ²⁶ Weightman had a plan for Bahrain and was well on the way to producing ones for Kuwait and the Trucial States by the time AOC Iraq sent an officer to survey the shaikhdoms' defence needs in early 1939.

The political agent's interim defence plan for Bahrain centred on protecting BAPCO's facilities, plus the Muharraq aerodrome and the wireless station. It called for enhanced asset security and building up local security forces, including the Bahrain State Police and a guard force made up from BAPCO employees. ²⁷ BAPCO, whose activities were spread over several areas of Bahrain (see Fig. 1), supported these security measures. The company ordered barbed wire for the refinery complex and enlisted more local guards. ²⁸

The AOC-Iraq's later defence schemes for the shaikhdoms also called for building up the Bahrain State Police and forming an armed volunteer defence force recruited from predominantly European personnel of BAPCO, which would be led and trained by a regular military officer. ²⁹ This officer, later named Defence Officer Bahrain, was also responsible for coordinating local defence arrangements across all the shaikhdoms. ³⁰

The defence scheme for the Trucial States focused solely on maintaining air communication in Dubai and Sharjah. At that time, British Overseas Airways Corporation (BOAC) flying-boats landed up to eight times a week in Dubai Creek with infrequent landings of RAF flying-boats. Disrupting these flights was easy: a matter of an adversary shooting at the low and slow aircraft, or anchoring small boats in the ‘fairway’ to make landing impossible. ³¹ BOAC and the RAF also landed at the Sharjah civil aerodrome, which possessed a fort-like rest house for travellers. The defence scheme judged that if an attack on these twin assets came, it would come by sea. Thus, the best defence for the landing areas was through maintaining British naval and air supremacy in the Gulf. Although an attack from the desert interior was considered unlikely, the British did provide some additional weapons to the ruler of Sharjah to better arm his retainers (askars or rijaal al-shaikh in Arabic). ³² Since 1932 local tribal guards organised by the ruler of Sharjah and paid for by BOAC (and its predecessor, Imperial Airways) had protected landed aircraft and the rest house. ³³

Nestled between Iraq and Saudi Arabia, tiny Kuwait was geographically the shaikhdom most vulnerable to a cross-border coup de main. In contrast to the 1950s onwards, Kuwait was then of little value to Britain. ³⁴ Protection would remain as it had been for decades: a combination of the ruler's own forces for internal security defending Kuwait Town, and British forces in Iraq preventing hostile forces from attacking Kuwait. ³⁵ For the latter, AOC-Iraq's staff concluded that RAF's aircraft and armoured car squadrons could, provided they had early intelligence of an attack in the making, defeat any adversary traversing the open desert before they reached Kuwait Town. ³⁶ In Qatar, which was the least significant of the shaikhdoms in terms of British interests, security was left to the ruler.

Britain's declaration of war on Germany on 3 September 1939, brought the Empire – including the British informal empire in the Gulf – into what would become a global conflagration. Despite the existence of the approved defence schemes for the shaikhdoms, limited on-the-ground changes had taken place in the months that followed. For example, in Bahrain the volunteer force had not formed up and there was no sign of the Defence Officer's arrival due to Army HQ India's inability to locate a suitable volunteer. ³⁷ None of the shaikhdoms had received their promised quota of Bren guns. ³⁸ This was unsurprising. Due to Britain's relatively late rearmament and mobilisation – particularly where the Army was concerned – there were insufficient Bren guns for the British Army, let alone anyone else. ³⁹

The lack of action partly reflected the ‘Phoney War’ stage of the Second World War. Following the fall of France in June 1940, Italy's entrance into the war that same month, and a general fear of British retreat from East of Suez, defence preparations in Bahrain and elsewhere in the Gulf were stepped up. ⁴⁰

Bahrain police, under the command of the ruler's privately employed British adviser, implemented a program to protect BAPCO's facilities that included motorcar, horse and camel patrols of the oil field. ⁴¹ The Defence Officer position was filled locally by the government of Bahrain's price control officer, Byard, a former cavalry officer. Despite his wide remit – which included advising and training the various local forces in Kuwait, Qatar, and the local guard force at the Sharjah rest house – Byard spent most of his time on Bahrain matters, forming up the oil company's defence volunteers and commanding the newly established Special Defence Police for anti-sabotage duties. ⁴² Given the challenge of protecting BAPCO's widely dispersed facilities – there were 70-odd oil wells some of which had been sealed off – the Special Defence Police were an important asset. Britain assigned them a training team from the RAF's Iraq Levies. ⁴³

The BAPCO volunteer force was ultimately a failure. The political resident deemed its members ‘too young, not disciplined for wearisome routine’, and men who avoided work and ignored instructions. To bring greater discipline, BAPCO hired a dozen British ex-servicemen as special constables. ⁴⁴ This remedy also proved a ‘total failure’, with five constables resigning or being dismissed because of drinking on the job or other unacceptable behaviour. ⁴⁵ The residency asked for a police inspector and several sergeants from various British Indian police forces, but were told by the Government of India that ‘as war is now at the door of India, it is impossible for Government of India to press Provincial Governments to provide European sergeants for Bahrain’. ⁴⁶

Suitable defence arrangements in Bahrain and the other shaikhdoms became more pressing as the Axis threat to the region materialised over the course of the war. Indeed, all three Axis powers at one time or another threatened some British interests in Eastern Arabia and nearby waters. To their credit, British officials had been correct in their assessment that Bahrain was the most likely target for enemy action. They were proved mistaken, however, in entirely dismissing a possible Axis attack from the air.

Reacting to Italian Action

Italy was the first of the Axis powers to threaten British interests in the Gulf. When Mussolini's Italy joined the war, the likelihood of the maritime threat increased perceptibly. The Italian Royal Navy (Regia Marina Italia) had a sizeable naval force based in the Red Sea port of Massawa in Italian Eritrea consisting of seven destroyers, five motor torpedo boats and eight submarines. Thus, Italy's Red Sea Flotilla was a serious enough force to threaten shipping travelling between the Mediterranean and the Indian Ocean along the Red Sea route as well as along the coasts of the Arabian Peninsula and East Africa. It was certainly a more substantial threat than the small number of German merchant raiders that occasionally operated in the Arabian Gulf between 1940 and 1941.

In mid-June 1940, Italy sent a Brin-class submarine, Luigi Galvani, to lay mines and attack vessels near the Strait of Hormuz. On 23 June, a sloop of the Royal Navy's Persian Gulf squadron, HMS Falmouth, spotted the submarine on the surface. It fired its 4-inch gun, hitting the submarine before grazing the diving submarine by riding over it. It then dropped depth charges, forcing the submarine to the surface. Damaged, the submarine sank rapidly, taking with it twenty-six of its fifty-seven crew. ⁴⁷

By the end of June 1940, four of the Red Sea Flotilla's submarines had been sunk or captured. The main motivation for the Allied campaign against the flotilla was not to protect the Gulf; it was to circumvent a U.S. Congressional moratorium on American merchant ships operating in a war zone, as well as clear the southern approach to Suez. ⁴⁸ Offensive submarine operations effectively ended around this time, as did most ranged operations by the flotilla. This was due to a combination of Allied patrolling and interdiction activities plus problems faced by the Italians, notably fuel shortages, technical deficiencies, and leadership failure. In the first half of 1941, the four surviving Italian submarines were relocated to a base in France to support the Germans in the battle for the Atlantic. In April 1941, the Red Sea Flotilla ceased to exist with its vessels mostly sunk or scuttled when the Massawa base fell to the British. But the Italian threat to British Gulf interests was not confined to the sea.

On the night of 19 October 1940, the Gulf shaikhdoms experienced their first, and only, direct attack when the Regia Aeronautica Italiana launched a bombing raid on Bahrain. Mussolini had approved a plan developed by test pilot Captain Paolo Moci to bomb the oil refinery in Bahrain using five long-range Savoia-Marchetti SM.82 aircraft for the operation. Four aircraft were converted to bombers while the fifth was in a cargo configuration and loaded with aviation fuel to refuel the aircraft if they were forced to land in the desert. Of the four bombers that took off from Rhodes, three arrived to drop bombs on BAPCO's refinery. They then continued to Italian Eritrea, travelling a total distance of 4,200 km with a flight time of 15 hours. ⁴⁹

Well lit as part of the counter-sabotage strategy to deter intruders, the refinery was easy to spot for the bomber pilots. ⁵⁰ No black-out was in place at the refinery – or anywhere else in the shaikhdoms for that matter – as an air attack was thought implausible. Although the raiders dropped eighty-four bombs, they targeted an area between two waste gas flares, believing this to be the location of the critical parts of the refinery. ⁵¹ The bombs fell harmlessly into an area near the coke pile. ⁵² One aircraft got lost on route, and bombed the Saudi Arabian Dhahran oilfield. It subsequently saw Bahrain and re-joined the flight.

Despite its ineffectiveness, this solitary air attack on the Gulf, along with the ongoing threat from submarines and merchant raiders, led British planners to reconsider the need for not only both anti-aircraft and coastal defences, but also more capable land forces to defend against parachute-dropped or submarine-landed raiding parties.

Even before the Italian air attack, the political resident complained Bahrain's defence scheme was ‘not working at more than 10% efficiency’. ⁵³ Protecting oil production was important in itself but so was the need to demonstrate a determination to defend the shaikhdom. Without this assurance, the political resident warned, there was a ‘grave risk of precipitating evacuation of American oil personnel with consequent loss of [oil] production’. ⁵⁴

Asked by the political resident to specify the requirements for mounting a reasonable air defence of BAPCO's refinery complex, the SNOPG advised that eight anti-aircraft guns and four searchlights were needed. ⁵⁵ The Royal Navy immediately landed a high-angle obsolete naval gun: a quick-firing 12-pounder anti-aircraft adapted as a coastal defence gun. ⁵⁶ It also organised for two more to be sent, but could not provide the three-dozen men needed to continuously man the planned three-gun defence. ⁵⁷ Undermining defence was the lack of an early warning system to identify approaching aircraft. ⁵⁸ Some steps were made to rectify this through listening posts and improvised apparatus (which was ineffectual and scrapped). ⁵⁹ BAPCO's parent company, the California Arabian Standard Oil Company (CASOC), agreed to equip its outstations in the eastern part of the Gulf with radios and instructions to contact BAPCO's headquarters if planes were seen. ⁶⁰

The political resident turned to various entities to help with Bahrain's air defence. AOC-Iraq said it could provide some gun crews and a searchlight, two high-angle mounts for Bren guns but no anti-aircraft guns. ⁶¹ The Government of India provided two complete gun crews plus reliefs in early 1941 as well as an anti-aircraft detachment from the Hong Kong and Singapore Royal Artillery which arrived from Aden. Less forthcoming, the Air Ministry advised that it could not spare fighter aircraft as every plane in the regional theatre was needed for operations in the western parts of the Middle East and Greece. ⁶²

Making AOC-Iraq responsible for local defence schemes in Eastern Arabia had proved less than ideal. RAF planners neither had sufficient knowledge of local affairs in the lower Gulf, nor did they have resources to spare for properly furnishing a defence scheme. In June 1941, the arrangements changed when British India became responsible for all land defence measures in the Gulf, except for Kuwait due to the neighbouring presence of RAF forces in Iraq. Air operations in the Gulf, however, remained under AOC-Iraq. ⁶³

German Advances to the North

From early 1941 until early 1943, the Allies fretted that German forces could invade northern Iraq and Iran, allowing them to push on to the Gulf or, at the very least, establish air bases from which to attack British assets in and around the Gulf. In 1941 Britain launched two pre-emptive operations, each of which sought to replace the ruling regimes sympathetic to the Axis. The first was the invasion of Iraq (18 April-31 May 1941); the second, an advance into Iran in concert with Soviet forces (25 August-September 1941).

Although British Mandatory Iraq came to an end in 1932, Britain had ensured its oil interests were protected and that it could maintain air bases in the newly independent country. On 1 April 1941, the then pro-British regime in Iraq was overthrown in a coup supported by the Iraqi army and air force and aided by German agents. A nationalist and pro-Nazi government was formed headed by Rashid Ali Al-Gaylani. The German influence over the Iraqi government – coupled with the recent presence of German war planes in Vichy airfields in Syria and the threat from Axis forces west of Suez – turned British military planners’ attention to the northern Gulf. If Iraq was lost to the Axis, it would not only result in Iraqi oil fields falling to the enemy, but it would sever communications and the critical air route between India and Egypt. It would also provide Germany with a launchpad to attack British interests further down the Gulf. But it was northern oil fields, especially those in the province of Kirkuk, that were of most concern to the British. Without Mesopotamian-sourced oil, the Royal Navy would have struggled to continue the fight in the Mediterranean and the British Army would have ground to a halt in North Africa.

To push Britain out of Iraq, Rashid Ali Al-Gaylani ordered Iraqi forces to attack RAF Habbaniya. British forces successfully defended the base, routing the attacking and follow-on Iraqi units. Meanwhile British Indian forces invaded Iraq from the south, landing in Basra on 18 April 1941 and marching north to Baghdad, and the west, from the British Mandate of Palestine. Despite Luftwaffe assistance, the Iraqi military was overwhelmed and on 31 May the Iraqi government signed an armistice, returning the king-regent to the throne.

The German air and land threat to British interests in the Gulf did not dissipate after Britain returned its Hashemite allies to the throne. Hitler's June invasion of the Soviet Union meant German forces might be in reach of the Gulf through Anatolia or the Caucasus. A more proximate concern was Germany's influence in Iran, which had been growing since the 1930s. Indeed, by 1941 Iran had become the centre of German intelligence and influence operations in the region. British military planners were concerned that Berlin could translate this influence into air bases for conducting aerial bombing, minelaying, and raids, or attacks by airborne troops in the Gulf, threatening vital communications lines between India and Iraq and oil interests in South Iran and Bahrain. In response, the British beefed up their anti-aircraft capabilities in Eastern Arabia. ⁶⁴ More consequentially, Britain invaded southern Iran on 25 August 1941 with ground, sea and air thrusts from several Iranian Gulf-facing ports and eastwards from Baghdad. Soviet forces, meanwhile, pushed southward. Within a few weeks, Reza Shah Pahlavi was forced to abdicate in favour of his pro-British son, Mohammad Reza Pahlavi.

The interventions in Iraq and Iran ended the German threat from the north-west but not from the north-east. The thrust by Axis forces on the Eastern Front had reached the Caucasus by July 1942, and given their momentum had the potential to invade Iran. This would see Axis land forces threatening the north-west end of the Gulf.

While this threat was developing, the rapid Japanese successes of early 1942 had put all of the Indian Ocean including the Gulf into the danger zone. The worst-case scenario for the Allies at the start of 1942 was the linking up of German and Japanese forces in the Iranian region. This explains why the British efforts to improve the defence of the Gulf states increased markedly early in 1942 and continued until early 1943 by which time the advances of the two Axis forces had stalled.

Starting in early 1942, Britain improved Bahrain's defence through deploying British Indian troops for anti-aircraft and coastal defence, and implementing air raid precautions. Captured weaponry arrived to bolster defences, including two Italian artillery pieces and six Italian machine guns. ⁶⁵ This material appears to have been of limited utility. For example, the machine guns stayed in storage at the British political agency throughout the war, probably due to their lack of ground fittings as they had previously been mounted in armoured vehicles. ⁶⁶

The number of British military personal in the Gulf swelled to 1,000 in Bahrain by December 1942 and many dozens in Sharjah. ⁶⁷ These numbers only increased as these locations became important staging posts on the Southern Gulf Reinforcement Route, transferring forces from the west to the eastern campaigns. In 1942 Britain also permanently stationed RAF squadrons in the shaikhdoms for the first time – in Bahrain and Sharjah. These comprised long-range aircraft to protect shipping – especially convoys moving war supplies via the Gulf to Russia and southbound for the Far East build up – from submarine and merchant raiders and also to carry out aerial guerre de course operations. The use of ageing or obsolete equipment was a feature of the combat aircraft the RAF deployed to the region. When in January 1942, the RAF commenced anti-submarines patrols in the Arabian Gulf and the Gulf of Oman out of Sharjah, and until the time it ended in April 1944, aircraft no longer suitable for the European front were used. Initially the aircraft were Vickers Vincent biplanes, then Bristol Blenheims and finally Wellington Mark XIIIs. RAF aircraft also included flying boats to undertake search and rescue. ⁶⁸

To accommodate the deployment of new air assets, upgrade work commenced at the existing civil aerodromes at Muharraq in Bahrain, at Sharjah, and also the establishment of new bases on the barren small Masirah Island off the south coast of Oman and at Salalah in the Omani Dhofar province. This rapidly expanding military footprint in Eastern Arabia required a rethink as to local means of security. The initial solution adopted by the RAF was to form up a locally recruited force called the Persian Gulf Levy Force to guard facilities in Bahrain and Sharjah. ⁶⁹ Most volunteers were pearl divers who considered guard duties an easier life than diving. In Bahrain, where three companies were set up, these levies were blamed for stealing, including prized ammunition and general goods, from the planes they were supposed to be guarding. ⁷⁰ Consequently, the RAF decided to replace the Persian Gulf Levy Force with the RAF's Iraq Levies. ⁷¹

A program of oil defence and denial was also implemented in 1942. This added to the limited protective measures introduced in the past few years. The British were concerned that oil production could be captured and exploited, or denied to the Allies. The solution adopted for the small-output oilfield in Qatar was simple: plugging the handful of producing wells with concrete and remove all equipment and facilities. This would prevent Axis forces from easily being able to extract oil for their use, as well as from blowing up the well-heads to allow the pressurised oil to flow uncontrolled to the surface and thus draining the reservoir. The denial order for Qatar was given by General Headquarters (GHQ) Middle East Forces in June 1942. ⁷² The situation in Bahrain was more complex. Closing oil production was not possible due to the Allies' need for it. Consequently, the response was a combination of denial and defence measures. Around forty-four non-producing wells were plugged, the well-heads of around eighty producing wells were hardened, and protective masonry barriers were put around the oil holding tanks. ⁷³ Work on these measures started in April 1942 and would only end in March 1943. ⁷⁴

While the halting of both the German and Japanese advances by the end of 1942 and early 1943 ended the physical threat to Bahrain, Allied interests in the Gulf and western Indian Ocean would continue to be threatened by submarines and surface raiders.

Axis’ Final Swansong

Even before Japan's surprise attack on British, U.S. and allied forces in the Pacific and Asia in December 1941, Britain's Chiefs of Staff considered what Japanese involvement in the war might mean for the Gulf, concluding that the Japanese navy posed no threat unless it had an advance base in the Indian Ocean, such as might be acheived by capturing Ceylon. If this did not occur, the threat would be limited to ‘occasional submarines and possibly sporadic operations by surface raiders’. ⁷⁵ As an insurance policy, the defence chiefs recommended developing aerodromes and landing grounds in the Gulf region as well as laying down stocks of fuel and munitions should sea communications need defending from expanding Japanese activity in the Indian Ocean. ⁷⁶ Indeed, Tokyo had shown an interest in Bahrain before the war. In early 1938 the Japanese ship Sata visited Bahrain on what was an intelligence collection activity. The ship was manned by personnel from the Japanese Imperial Navy who, on the pretext of purchasing a consignment of fuel oil, snooped around Bahrain, even requesting an inspection of BAPCO's facilities. ⁷⁷

With the loss of Singapore in February 1942 and the British retreat over the Indo-Burmese border into India soon after, Britain had lost its footing in the East. The next target was Ceylon, and if this fell, then Japan was free to penetrate deep into the Indian Ocean.

In a post war reflection on what was the most dangerous moment of the Second World War, Churchill nominated this time – specifically the period around when the Japanese fleet was approaching Ceylon. ⁷⁸ Despite Japan not winning Ceylon, there remained for many months concern over air raids on ports and vital oil installations in the Gulf. This is reflected in a July 1942 note from the Chiefs of Staff which stated that preparing for this danger was now the ‘highest priority’. ⁷⁹

To provide early warning to the air and ground anti-air defences of Abadan, Basra and Bandar Shahpur areas of an impending air attack from an easterly or south-easterly direction, the RAF worked to set up a network of water-borne and land-based wireless observation posts in the Gulf. The water-borne posts consisted of a dozen dhows (local wooden vessels) which spanned the Gulf from Ras al-Mutaf on the Persian coast to the Ras Rakan at the northern point of Qatar. ⁸⁰ The land-based observation posts consisted of four posts on the north and eastern coast of the Qatari peninsula, which juts into the Gulf. ⁸¹

In Bahrain the fear was not only of bombing but also of Japanese paratrooper drops and marine raids from submarines. ⁸² (The latter was more unlikely due to the lack of a suitable port in Bahrain and shallow water around the islands, meaning maritime forces would have to remain several miles offshore in open and unprotected water as men and materiel were moved ship-to-shore). The BAPCO guard force, whose main job was to prevent thievery, was now tasked with looking out for and reacting to Japanese parachutists in case Bahrain was subject to a raid by airborne troops. ⁸³

The main concern, however, was that Japanese (and German) submarines and merchant raiders would target shipping across the Indian ocean, including vital oil supplies out of the Gulf and the growing freight coming into Basra and the Iranian ports to feed the Persian Corridor which transported materiel for the Soviets. Aerial and maritime assaults never materialised but there were submarine attacks by both Japanese and German submarines on shipping outside the Gulf. The Japanese submarine threat in the Indian Ocean dates to early 1942. Operating out of Vichy French-controlled Madagascar, Japanese submarines attacked shipping mainly in the southern Indian Ocean and on the routes to and from Southeast Asia.

Following the loss of Madagascar to the British in November 1942, Japanese submarines began operating remotely in the western Indian Ocean, without local points of resupply but with some success against Gulf shipping. For example, a Type B-1 class I-27 large Japanese submarine, which carried a float plane, was credited with sinking twelve ships, including a number off the coast of Oman and in the Gulf of Aden. ⁸⁴ A February 1943 British intelligence assessment judged that the Japanese were seeking to establish a presence on the coast of Iran so as to resupply submarines operating in the area and have a more enduring presence. ⁸⁵ Creating a covert support base was given credibility due to Japan's pre-war trade interests in the Gulf of Oman and Iran, which provided them with geographic knowledge and contacts. ⁸⁶

Japanese submarines continued to operate in the western Indian Ocean into 1944. ⁸⁷ They were briefly joined in 1943 by a German force of submarines, known as Gruppe Monsun (Monsoon Group), which shifted from the Atlantic to operate out of the Japanese captured Malay port city of Penang. On the way they hunted vessels across the Indian Ocean as far north as the Arabian Sea. Gruppe Monsun's submarines attacked (and sank) vessels in the Arabian Sea, the Gulf of Oman, and the Red Sea until early 1944. ⁸⁸ Some of the Gruppe Monsun submarines, however, would later fall prey to British anti-submarine operations launched from the shaikhdoms. ⁸⁹

By early 1943, Axis advances had stopped. The Germans had been defeated at El Alamein the previous November and at Stalingrad that February; the Japanese advance in Asia slowed, and their sea presence diminished. For the remainder of the war, the Gulf and especially Bahrain would remain important to Britain for its oil, as a staging post on the imperial air route, and as the base of the Royal Navy's Gulf Squadron. For the wider Allied war effort, the Gulf became a crucial link in the transportation of military aid to the Soviet Union. ⁹⁰ In the final years of the war, the region no longer faced any direct threats, apart from some submarine attacks which continued into 1944. Certainly by 1945, the need for convoy escorts and anti-submarine patrolling had ended. What is more, Britain was able to deploy more aircraft, which, although second line and unsuitable for the main theatres, added considerable capability to the Gulf. ⁹¹

As the threat diminished and the defence requirements lessened, military activity, however, mushroomed. From early 1944, Eastern Arabia became increasingly involved in the air reinforcement route to India to support the eastern campaigns by both British and American forces. Large numbers of tactical fighters and transport aircraft carrying materiel and personnel passed through the RAF facilities at Bahrain, Sharjah and Masirah off Oman. ⁹² Japan's surrender in September 1945 saw the movement of personnel reverse along the Southern Gulf Air Corridor as they returned home and demobilised. Military traffic along the corridor declined rapidly by 1946, with the RAF facilities at Bahrain and Sharjah being mothballed.

Conclusion

Throughout the Second World War, the shaikhdoms of Eastern Arabia and nearby waters constituted, relative to the main fronts of the war, a peripheral theatre for Britain. Yet, the region was far from inconsequential and grew in significance to the Allied war effort as a logistical gateway and communication node. Whilst never seriously at risk of falling under Axis control or suffering sustained heavy attacks – the Gulf lay at the extreme limits of the Axis strategic reach – the British-protected region was at times threatened from air and sea.

Britain's evolving defence scheme in the Gulf provides a window into the organisational, manpower and materiel attention that major powers with overseas possessions and responsibilities give peripheral theatres. Moreover, the Gulf theatre was one where responsibility for defence was shared across multiple political and military agencies. As each agency had differing priorities, and these changed with time, assessments of the region's importance to Britain and the threat to these interests varied. One observation for the Gulf theatre – and one that may be generalisable to other parts of the British Empire, informal or otherwise – is that the officials most important in terms of defence arrangements were not military officers but Britain's political representatives. In this case, the political resident and his political agent. Pre-war, they tried to raise awareness in London and India as to the importance of this area, and initiated defence schemes for the shaikhdoms while waiting for the responsible military command to start its own. During the war, they played a key role in liaison, coordination and problem identification between the different political and military agencies and served in effect as the theatre's strategic planner and local fixer. They developed on-the-ground workarounds and marshalled local resources when responses or resources from military authorities were slow or inadequate. This points to the importance of a well-connected and activist local leader in areas which are of secondary interest to military commands.

Another observation provided by this case is that the provision of military manpower and materiel, and the speed of response for the Gulf theatre was always going to be slow in coming and unsatisfactory to those requesting aid. As combat theatres always took priority, the shaikhdoms’ defence had to rely on obsolete, captured and improvised equipment. Some of this was worthless, such as the captured Italian machine guns and the locally built aircraft sound detector. Yet these ad hoc measures likely made those acting to shore up Britain's position in the Gulf believe they were taking action, and may also have influenced the perception of the local rulers that their protector was active.

Importantly, Britain's Gulf planners also saw the need to assist in the development of local forces, which took a number of forms. One was to develop a local militia of mostly Europeans, another was to strengthen the guarding force of the oil company by using discharged soldiers and serving police, and the third was to provide personnel, training and equipment for the armed retainers and police forces under the control of the local rulers. These arrangements were often of limited success without the support of regular British and British Indian professional military and police personnel to lead, administer, train and man them. Despite this surge of wartime interest in local forces, it would not be until oil production took off in the area and Britain planned its departure – as part of its 1968 decision to accelerate its withdrawal from East of Suez – that London would press the local rulers to establish professional militaries of their own.

While military history scholarship is attracted towards decisive battles and strategic theatres, this article offers an insight into areas which are given less attention – peripheral theatres. These were not the sites of major battles nor the places which needed to be protected at all costs. Nevertheless, they were important as their loss would have caused significant challenges for the prosecution of the war.