As North Vietnamese troops surged forward, the fragile peace in South Vietnam began to unravel. The 1975 Spring Offensive, launched on December 13, 1974, marked a decisive turn in the Vietnam War. With the US having withdrawn its troops, the North Vietnamese army, backed by China and the Soviet Union, sensed victory within their grasp. Led by Generals Van Tien Dung and Tran Van Tra, the North Vietnamese forces poured across the demilitarized zone, rapidly gaining ground against the beleaguered South Vietnamese army. Panic set in as cities fell, and the South Vietnamese government teetered on the brink of collapse. By April 30, 1975, Saigon had fallen, and the war was all but over.