US bombing, use of chemical weapons, napalm and phosphoric bombs as well as the ground operations of the US army caused the death of 3 million Vietnamese in the Vietnam war.
The exact number of casualties in the Vietnam War, particularly the number of deaths caused specifically by US military operations, is not known because reliable data is not available. Estimates vary considerably, but none come close to approaching the figure of 3 million. The Vietnamese Foreign Ministry cites several of these studies. For example, Guenter Lewy estimated that around 220,000 civilians in South Vietnam were killed in US, Army of the Republic of Vietnam and other allied land operations. In another study, Benjamin Valentino attributes 110,000-310,000 “counter guerrilla mass killings” to U.S. and South Vietnamese forces during the war. Estimates for the number of North Vietnamese civilian deaths resulting from US bombing range from 30,000-65,000, while higher estimates place the number of civilian deaths caused by American bombing of North Vietnam in Operation Rolling Thunder at 182,000.
Finally, according to an official estimate by Hanoi made in 1995, the total number of civilian deaths in the whole war was almost 2 million people, which is four times higher than other estimates. Even if this number is accurate, it is still significantly less than the 3 million claimed in this article.