Final answer:
The statement is true; during the Vietnam War, the U.S. dropped more bombs than the total dropped by all sides in World War II, with Operation Rolling Thunder marking a significant portion of this bombardment.
Step-by-step explanation:
It is true that American planes dropped more bombs in Vietnam than had been dropped on Germany and Japan during World War II During a period known as Operation Rolling Thunder, the United States executed a bombing campaign from 1965 to 1968 wherein they dropped an extensive amount of ordnance on targets throughout Vietnam. This ordinance exceeded the total amount used by all belligerents during the entirety of World War II.
By the end of the Vietnam War, the total tonnage of bombs dropped was approximately 14 billion pounds, which averages out to roughly 500 pounds of explosives per individual in Vietnam.
Despite the massive scale of this bombardment, it failed to achieve its military objectives or garner support for the South Vietnamese government.