What were the casulties for the U.S. in the Vietnam war?
In excess of 53,000 dead. A little over 58,000 U.S. Troops dead.
For me Vietnam defeated US in the Vietnam War. Because North Vietnam conquered Southern Vietnam. And Southern Vietnam is a democratic country and an ally of US. The US Military was restricted by the political situation and was not able to wage war in an effective manner. Because of political pressure, the necessary military resources could not be deployed.
Vietnam is a war which the US definitely lost because the goal of the war was to support the Republic of Vietnam (aka South Vietnam) and prevent it from falling to the Democratic Republic of Vietnam (aka North Vietnam). Despite massive effort and sacrifice on the part of the US, South Vietnam collapsed in 1975.
The Americans did not make war with Vietnam. There was no Vietnam. There were two countries: NORTH Vietnam and SOUTH Vietnam. NORTH Vietnam attacked SOUTH Vietnam. The US (Americans) defended SOUTH Vietnam. The US never invaded NORTH Vietnam (the US bombed it though). NORTH Vietnam invaded SOUTH Vietnam. NORTH Vietnam was (and still is) a communist nation. The US was against communism.