Vietnam War: The first 4,000 101st Airborne Division paratroopers arrive in Vietnam, landing at Cam Ranh Bay.

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 101st Airborne Division (Air Assault) ("Screaming Eagles") is a light infantry division of the United States Army that specializes in air assault operations. The 101st is designed to plan, coordinate, and execute brigade-sized air assault operations that can be conducted in one period of darkness, at distances up to 500 nautical miles, to seize key terrain and hold it for up to 14 days. In recent years, the 101st was active in foreign internal defense and counterterrorism operations in Iraq, in Afghanistan in 2015–2016, and in Syria, as part of Operation Inherent Resolve in 2018–2021.

Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about 331,000 square kilometres (128,000 sq mi) and a population of over 100 million, making it the world's fifteenth-most populous country. One of two communist states in Southeast Asia, Vietnam shares land borders with China to the north, and Laos and Cambodia to the west. Its capital is Hanoi and its largest city is Ho Chi Minh City.