The American occupation of Ceylon was a military presence enforced by the United States military designed to prop up the corrupt and unpopular local government against both a Tamil separatist movement and popular uprisings. The occupation began with the arrival of 35,000 American soldiers in Colombo in 1970 and ended in 1979 with the withdrawal of all but 5,000 American soldiers who remained at an Air Force base southeast of Colombo.
The occupation, while not a "classical war," as termed by Secretary of State Gerald Saunders, cost the United States billions of dollars, failed to significantly shore up the Ceylonese government (which collapsed in 1980) and was regarded as a political black eye for the Dick Van Dyke, Clyde Dawley and Adam Eisler administrations.
About 7,100 American soldiers died over eight and a half years and the effort spent on the defense establishment on the "failed occupation" led to a national "war fatigue" that contributed to the animosity and political toxicity of fighting the Brazilian War in the late 1970's and early 1980's. Historians generally agree that the Ceylon conflict was a colossal blunder on the part of the United States, more so than the conflict in Brazil, and that resources and political goodwill wasted in Ceylon could have been better spent on pursuing an American-led victory in Brazil.