a result, the U.S. began a full-scale production of 2,4-D and 2,4,5-T and would have used it against Japan in 1946 during Operation Downfall if the war had continued. In the years after the war, the U.S. tested 1,100 compounds, and field trials of the more promising ones were done at British stations in India and Australia, in order to establish their effects in tropical conditions, as well as at the U.S. testing ground in Florida. Between 1950 and 1952, trials were conducted in Tanganyika, at Kikore and Stunyansa, to test arboricides and defoliants under tropical conditions. The chemicals involved were 2,4-D, 2,4,5-T, and endothall (3,6-endoxohexahydrophthalic acid). During 1952–53, the unit supervised the aerial spraying of 2,4,5-T in Kenya to assess the value of defoliants in the eradication of tsetse fly. Early use In Malaya the local unit of Imperial Chemical Industries researched defoliants as weed killers for rubber plantations. Roadside ambushes by the Malayan National Liberation Army were a danger to the British military during the Malayan Emergency (1948–1960) so trials were made to defoliate vegetation that might hide ambush sites, but hand removal was found cheaper. A detailed account of how the British experimented with the spraying of herbicides was written by two scientists, E.K. Woodford of Agricultural Research Council's Unit of Experimental Agronomy and H.G.H. Kearns of the University of Bristol. After the Malayan Emergency ended in 1960, the U.S. considered the British precedent in deciding that the use of defoliants was a legal tactic of warfare. Secretary of State Dean Rusk advised President John F. Kennedy that the British had established a precedent for warfare with herbicides in Malaya. Use in the Vietnam War In mid-1961, President Ngo Dinh Diem of South Vietnam asked the United States to help defoliate the lush jungle that was providing cover to his Communist enemies. In August of that year, the Republic of Vietnam Air Force conducted herbicide operations with American help. Diem's request launched a policy debate in the White House and the State and Defense Departments. Many U.S. officials supported herbicide operations, pointing out that the British had already used herbicides and defoliants in Malaya during the 1950s. In November 1961, Kennedy authorized the start of Operation Ranch Hand, the codename for the United States Air Force's herbicide program in Vietnam. The herbicide operations were formally directed by the government of South Vietnam. During the Vietnam War, between