In doing so, they had considerable support from like-minded American officials. The basic weakness of Roosevelt's scheme was its dependence on Chiang Kai-shek the ruler of China. Chiang's regime virtually collapsed under Japanese pressures in 1944, and Japan overran the American airbases that were built to attack Japan. The Pentagon's plans to use China as a base to destroy Japan collapsed, so the U.S. Air Force turned its attention to attacking Japan with very long-range B-29 bombers based in the Pacific. The American military no longer needed China or Southeast Asia. China clearly was too weak to be a policeman. With the defeat of Japan, Britain took over Southeast Asia and returned Indochina to France. Roosevelt realized his trusteeship plan was dead, and accepted the British-French actions as necessary to stabilize Southeast Asia. By the end of the war, several states, including all of Latin America, had joined the Allies. Roosevelt's appointment of young Nelson Rockefeller to head the new, well-funded Office of the Coordinator of Inter-American Affairs provided energetic leadership. Under Rockefeller's leadership, the U.S. spent millions on radio broadcasts, motion pictures, and other anti-fascist propaganda. American advertising techniques generated a push back in Mexico, especially, where well-informed locals resisted heavy-handed American influence. Nevertheless, Mexico was a valuable ally in the war. A deal was reached whereby 250,000 Mexican citizens living in the United States served in the American forces; over 1000 were killed in combat. In addition to propaganda, large sums were allocated for economic support and development. On the whole the Roosevelt policy in Latin America was a political success, except in Argentina, which tolerated German influence, and refused to follow Washington's lead until the war was practically over. Outside of Latin America, the U.S. paid particularly close attention to its oil-rich allies in the Middle East, marking the start of sustained American engagement in the region. The main American role in the war, beyond the military mission itself, was financing the war and providing large quantities of munitions and civilian goods. Lend lease, as passed by Congress in 1941, was a declaration of economic warfare, and that economic warfare continued after the attack on Pearl Harbor. Roosevelt believed that the financing of World War I through loans to the Allies, with the demand for repayment after the war, had been mistake. He set up the Lend Lease system as a war program, financed through the military budget. As soon as the war with Japan ended it was terminated.