The US did not kill two million, although the war did.

The invasion was of the south by the north. The US was invited in by the government of the south.

The real reason we fought in Vietnam was to stop Soviet imperialism. The Soviets (specifically COMINTERN) trained and sent Ho Chi Minh to French Indochina in order to seize the region from the French, on behalf of the USSR. Yes, some lies were told about the US’s reasons — we were more concerned with stopping the communist tyranny than with “preserving democracy.”

In Vietnam, the North and South were different cultures, and thus the country was split by the treaty (which was promptly violated by the North). People were allowed under the treaty to migrate to the side they preferred, although the communist North tried to prevent people leaving for the south, even as it encouraged it’s Viet Minh cadre to stay in the south in order to foment revolution against South Vietnam. An acquaintance was one who escaped to the South, but only by evading the secret police in the North. He went on to join the South’s air force and fight the North as a Cobra helicopter pilot.

After the 1968 Tet Offensive, the majority of South Vietnamese had concluded that they would be better off with the corrupt autocracy of the South than the tyrannical corrupt autocracy of the North. The atrocities pre-planned attrocities committed by the North’s forces in Hue during that offensive cemented their understanding that the communists would be terribly brutal. The one million or so “boat people” fleeing the communists after the takeover is testament to that.

The North only won the war after the left in the US took over Congress and hobbled US efforts to help the South, even as the Soviet Union massively armed the North. The final invasion was led by a tank force larger than Patton’s World War II formations against a South with little ammunition, and with equipment largely inoperative due to lack of spare parts — thanks to the US congress.

The left in the US should apologize to the Vietnamese for allowing the conquest by the brutal communists. That was our real sin in Vietnam.

As to casualties — the US scrupulously sought to avoid civilian casualties in both countries. The NVA/VC, on the other hand, had no such qualms — in fact, atrocities were part of their tactics in order to control the rural population of the South during the war. In that, they failed — after 1972, the communists only controlled a small part of the South, even though all US troops were gone. The rural people, once given the means, and backed by conventional armed forces, had overthrown the VC terrorists.

Too bad that was in vain, because of the perfidy of the US Congress.