The Tet Offensive caught US military leaders by surprise.
The Tet Offensive was a series of offensive military operations by the North Vietnamese Army and the Viet Cong between January 30 and September 23, 1968, as part of the Vietnam War. It began as a surprise attack the day after the Vietnamese New Year, the Tet Nguyen Dan.
The Tet Offensive was a decisive moment in the Vietnam War; despite the failed military success, it constituted a great moral and propaganda victory for the Viet Cong and North Vietnam and caused a serious political crisis in the United States. Within a few weeks, President Lyndon Johnson decided to withdraw from political life and halt the escalation, starting peace talks.