The Tet Offensive was a massive, coordinated surprise attack by North Vietnamese and Viet Cong forces during the Vietnam War.

It was launched in January 1968 during the Tet (Lunar New Year) holiday, when a truce was supposed to be in effect.

Attacks were launched on more than 100 cities and towns across South Vietnam, including the capital, Saigon.

A key element was the dramatic assault on the U.S. Embassy in Saigon.

From a purely military perspective, the offensive was a major defeat for the communists, who suffered enormous casualties and failed to hold any of their objectives.

However, from a political and psychological perspective, it was a stunning strategic victory for them.

The scale and intensity of the offensive shocked the American public and shattered the official narrative that the U.S. was winning the war.

Media coverage of the brutal fighting dramatically increased anti-war sentiment in the United States.

In the wake of the offensive, President Lyndon B. Johnson announced that he would not seek re-election.

The Tet Offensive is widely considered the major turning point of the Vietnam War.