The area east of the Mekong, however, was soon wrenched back from Siam by the French, who wanted a buffer state to protect Vietnam, and set up Laos as a unified territory in 1907. Briefly occupied by Japan in 1945, a three-decade-long conflict was triggered when France wanted to retake its colony. Granted full independence in 1953, the war continued between a bewildering variety of factions, with the Communist and North Vietnam-allied Pathet Lao struggling to overthrow the French-leaning monarchy. During the Vietnam War (1964-1973) the United States dropped 1.9 million tonnes of bombs on Laos, mostly in the northeast: for comparison 2.2 million tonnes of bombs were dropped by all sides in World War II.