Tet Offensive

The Tet Offensive was a military campaign during the Vietnam War that started on 30 January 1968. It was fought by the communist forces of the Viet Cong in South Vietnam, which were aided by North Vietnam, against the South Vietnamese government, aided by the United States and other allies.
Its purpose was to surprise the enemy with attacks against military and civilian commands and control centers in South Vietnam.
Eventually, the Americans and the South Vietnamese managed to fight off the communist forces for a military victory. However, the massive fighting during the Tet Offensive made most Americans go from supporting the fighting in Vietnam to opposing it. The military and the government had told the Americans that the their country was close to winning. After that was disproved by the offensive, the US was said to have won the battle but to have lost the war.