The United States emerged as a player in Middle Eastern politics in 1919 when the King–Crane Commission travelled to the region of Greater Syria. From this humble beginning, Washington grew to dominate the political landscape of the region. In the early twentieth century, the anti-colonial history of the United States inclined local leaders to view Washington as a potential friend of the Arab nationalist endeavour. International relations are not, however, based on friendships. Realist understandings of state behaviour in the international system point to the primacy of the principle of self-interest. All states act with the intention of furthering their own position and that of their allies: the United States is no different. In the Middle East, the same principles apply. It is against this backdrop and the broader dynamics of international relations in the twentieth century that the role of the United States in the Middle East must be assessed.