The US government—which feared that poverty in the basin would contribute to the strength of communist movements—proved one of the most vocal international backers of the committee, with the U.S. Bureau of Reclamation conducting a seminal 1956 study on the basin's potential. Another 1962 study by U.S. geographer Gilbert F. White, "Economic and Social Aspects of Lower Mekong Development", proved extremely influential, resulting in the postponement of (in White's own estimation) the construction of the (still unrealized) mainstream Pa Mong Dam, which would have displaced a quarter-million people. The influence of the United States in the committee's formation can also been seen in development studies of General Raymond Wheeler, the former Chief of the Army Corps of Engineers, the role of C. Hart Schaaf as the Mekong Committee's Executive Agent from 1959 to 1969, and President Lyndon Johnson’s promotion of the committee as having the potential to "dwarf even our own T.V.A." However, US financial support was terminated in 1975 and did not resume for decades due to embargoes against Cambodia (until 1992) and Vietnam (until 1994), followed by periods of trade restrictions. However, Makim argues that the committee was "largely unaffected by formal or informal U.S. preferences" given the ambivalence of some riparians about US technical support, in particular Cambodia's rejection of some specific types of assistance. However, the fact remains that "international development agencies have always paid the bills for the Mekong regime," with European (especially Scandinavian) nations picking up the slack left by the United States, and then (to a lesser extent) Japan.