'Abcol' was the British overall plan for the defence of the Anglo-Iranian Oil Company’s installations in Iran (1939/42).

In 1925, after years of internal warfare, political and social unrest and foreign intervention, Persia was unified under the rule of Reza Khan, who crowned himself as Reza Shah in the course of the same year and in 1935 changed the name of the country from Persia to Iran. Reza Shah committed Iran to a very ambitious development programme of economic, cultural and military modernisation, and Iran now began rapidly to evolve into a modern industrial state. Among the host of improvements instituted by Reza Shah were the construction of infrastructure, the enlargement of cities and transportation networks, and the establishment of schools. Reza Shah also committed his country to neutrality but, to help finance and support his ambitious modernisation projects, required western assistance.

For a considerable period Iran and Germany, in the guise of the latter’s previous empire, had cultivated ties partly as a counter to the imperial ambitions of the UK and the Russian empire (later the USSR). The development of trade with Germany appealed to Iran because the Germans did not have a history of imperialism in the region.

Despite the fact that Iranian embassies in occupied European capitals rescued more than 1,500 Jews and granted them Iranian citizenship, allowing them to move to Iran, the British started to accuse Iran of pro-German sentiment. Although Reza Shah declared Iranian neutrality early on World War II, Iran assumed steadily greater strategic importance to the British government, which feared that the Abadan refinery complex of the UK-owned Anglo-Iranian Oil Company might fall into German hands. Producing eight million tons of oil in 1940, the refinery was a crucial part of the Allied war effort. Tension between the UK and Iran had been strained since 1931 when the shah cancelled the D’Arcy Concession, which gave the Anglo-Iranian Oil Company the exclusive right to sell Iranian oil, with Iran receiving only a small percentage of the revenue profit.

The 'Abcol' plan was eventually rendered superfluous by the British and Soviet occupation of Iran in 'Countenance' in |August and September 1941.