Two UH-1 'Huey' helicopters operate over a U.S. air base in South Vietnam as a column of dark smoke rises in the distance, a scene emblematic of the chaos of the Tet Offensive launched by North Vietnamese and Viet Cong forces in late January 1968. The coordinated surprise attacks struck dozens of cities, towns, and military installations across South Vietnam simultaneously, and photographs like this one - taken from the relative safety of a base perimeter - document the abrupt disruption of daily operations as air and ground units scrambled to respond. Project: 218418