What was the most serious blow to president Johnson's Vientam policy?

Answer 1

The Tet Offensive was the largest blow to the Johnson's Vietnam "Police policy".

The Vietcong along with the North Vietnamese Communist Army laid low for a

while. Just as Generals thought they had eliminated all of the Vietcong in South

Vietnam. The Vietcong and the N. Vietnamese army launched a large offensive on

several key cities including Saigon. Although in a weeks time the American troops

were able to re-claim all of the recently captured cities. The Tet Offensive

largest blow had been a political one. The offensive proved that the Vietcong

were still a very prevalent threat in South Vietnam