Vietnam War: Viet Cong guerrillas attack the United States embassy in Saigon, and other attacks, in the early morning hours, later grouped together as the Tet Offensive.

The Vietnam War was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam and South Vietnam and their allies. North Vietnam was supported by the Soviet Union and China, while South Vietnam was supported by the United States and other anti-communist nations. The conflict was the second of the Indochina wars and a proxy war of the Cold War between the Soviet Union and US. The Vietnam War was one of the postcolonial wars of national liberation, a theater in the Cold War, and a civil war, with civil warfare a defining feature from the outset. Direct US military involvement escalated from 1965 until its withdrawal in 1973. The fighting spilled into the Laotian and Cambodian Civil Wars, which ended with all three countries becoming communist in 1975.

The Viet Cong (VC) was an epithet and umbrella term to refer to the communist-driven armed movement and united front organization in South Vietnam. It was formally organized as and led by the National Liberation Front of South Vietnam, and conducted military operations under the name of the Liberation Army of South Vietnam (LASV). The movement fought under the direction of North Vietnam against the South Vietnamese and United States governments during the Vietnam War. The organization had both guerrilla and regular army units, as well as a network of cadres who organized and mobilized peasants in the territory the VC controlled. During the war, communist fighters and some anti-war activists claimed that the VC was an insurgency indigenous to the South that represented the legitimate rights of people in South Vietnam, while the U.S. and South Vietnamese governments portrayed the group as a tool of North Vietnam. It was later conceded by the modern Vietnamese communist leadership that the movement was actually under the North Vietnamese political and military leadership, aiming to unify Vietnam under a single banner.

Ho Chi Minh City, also known as Saigon, is the most populous city in Vietnam with a population of 14,002,598 in 2025.