Iron Triangle

In the Vietnam War, US name for a triangular area some 48 km/30 mi north of Saigon. By 1967 the Triangle had been overrun by Vietcong guerrillas, threatening Saigon and severely limiting US and South Vietnamese operations. The USA mounted Operation ‘Cedar Falls’ to clear the area and render it incapable of supporting Vietcong units.

About 15,000 US and South Vietnamese troops were deployed along the sides of the triangle, after which helicopter-borne and armoured forces entered the area, divided it up, and cleared each sector individually. All villages were destroyed and the civilian population removed to more secure areas; some 300 Vietcong guerrillas were captured and an estimated 250 killed. Once this ground search had been completed, US aircraft sprayed chemical defoliant on the trees so as to remove leaf cover and make the area open to aerial observation and suppressive fire.