Southern Asia 1941: Anglo-Soviet invasion of Iran
When Germany invaded the Soviet Union in June 1941, Iran’s strategic position and oil reserves became even more important to the Allied war effort than before. In August the British and the Soviets launched a joint invasion of the country, deposing the defiant Reza Shah and opening up a supply route to the Soviet Union.
Changes to the map 8 July 1941–29 August 1941
Anglo-Soviet invasion of Iran: The British have invaded southern Iran, occupying Ahvaz, Bandar Abbas, and Hamadan. In the north, the Soviets have occupied Tabriz, Rasht, and Mashhad and are advancing on Qazvin and Tehran.
French Indochina: The Japanese have moved into Saigon and occupied the south.
British Protectorates in the Persian Gulf
The British Residency of the Persian Gulf maintained British India's influence in a number of Gulf states from the 19th Century until 1947. These states were nominally independent - and shown as such in most atlases from the period - but all signed treaties guaranteeing British control over their foreign affairs.
The Sultanate of Muscat and Oman was the only one of these states with significant international relations, having obtained trade agreements with the US and France before it signed its treaty with Britain. Maps of the time often show Trucial Oman and even Qatar as regions of Oman.
Trucial Oman was the region to the west of Oman which collectively signed treaties with Britain. The sheikhdoms of this region were often called the Trucial States, and later became the United Arab Emirates. However at this time they had little unity, with no regional council until 1952.
The British Indian Empire, also known as the British Raj, was comprised of a complex of presidencies, provinces, protectorates, and agencies. Only the top level subdivisions are shown here.
The area under direct British rule was known as British India and made up of presidencies and provinces - a presidency simply being the name for an older province.
Outside British India, but often included within the sphere of the presidencies/provinces, were the hundreds of protectorates or 'princely states'. These were indirectly ruled states, the largest being Hyderabad, Kashmir, and Mysore. The others were either collected into agencies - which might in turn contain other smaller agencies - or fell under the sway of the provinces.
23–28 Jul 1941 Operation "FU"▲
In response to a Japanese ultimatum, Vichy France allows Japan to use air facilities and harbors in southern French Indochina. The Japanese proceed to occupy Saigon and other southern cities, with IJN vessels moving into the ports of Saigon, Tourane, and Camranh Bay.
26 Jul 1941 Freezing of Japanese assets▲
Following Japan's rejection of a United States-sponsored plan to withdraw from most of China and French Indochina and a Japanese agreement with Vichy France to allow Japanese troops into southern Indochina, the US froze Japanese assets. The United Kingdom and the Netherlands followed suit, depriving Japan of 90% of its oil imports.
25 Aug–17 Sep 1941 Anglo-Soviet invasion of Iran▲
In Operation Countenance, the United Kingdom and the Soviet Union launched a surprise attack on the Imperial State of Iran, after Reza Shah refused to expel German nationals. The British occupied the south including the oil wells of Ahvaz and advanced from Iraq to Hamadan, while the Soviets invaded the north, capturing Tabriz and Qazvin. With his army unable to halt the invaders, the Shah conceded defeat and a ceasefire was arranged on 29 August. The Soviets entered Tehran on 17 September, beginning the joint Anglo-Soviet occupation of Iran.