What effect did the Tet Offensive in Vietnam on the war?

Answer 1

Americans began to wonder if the could win the war

While the US Military killed thousands of communists invaders from North Vietnam and stopped the communist offensive dead in it's tracks, the US public seeing the battle on TV, at a time when LBJ and Gen. Westmoreland was saying; 'Peace is at hand', became divided over the war. Clark Clifford replaced Sec. of Defence Robert McNamara, and Clark Clifford recommended pulling out of South Vietnam. Walter Cronkite, respected CBS reporter, recommended pulling out as well. LBJ announced there would be peace talks with North Vietnam in Paris and he would not run for a second term.

Answer 2

It was in the Gulf of TonKin that a Vietnamese warship allegedly fired at a U.S. ship - considered an act of war, and so the Congressional resolution authorizing President Johnson to protect South Vietnam against the incursion of the communist North Vietnamese army was called the "Gulf of Tonkin Resuolution."

There is some controversy concerning the accuracy of the claim that a U.S. ship was actually fired on by North Vietnamese seamen.