Oil is a highly political commodity and has more than once taken the centre of the stage in international affairs. This is not surprising in view of its importance in industry and transportation as well as for military activities. Mesopotamian oil was a crucial consideration in a number of the political settlements in the Middle East after the First World War, with the French, British and Americans playing the leading roles, just before that war the British navy had converted to oil, and Britain considered the security of her oil supplies to be an important objective of foreign policy. She had no domestic production. In the 1920s the United States began to fear that her oil reserves were becoming dangerously depleted and she also felt that her security as well as her prosperity depended on obtaining control of oil abroad. The United States sought access to oil concessions in the Middle East, and the diplomatic skirmishes were sharp as the British and Dutch tried to keep her out, not merely from the Middle East, but from south-eastern Asia as well, where production was dominated by the Dutch. Thus oil was an important source of controversy in the foreign policy of a number of countries in the inter-war period.