Rogers Signs Paris Peace Accords: With US forces gone from the country, South Vietnam stood alone. The situation worsened in December 1974, when Congress passed the Foreign Assistance Act of 1974, cutting off all military aid. The North Vietnamese stormed through the south, finally capturing Saigon. South Vietnam surrendered on April 30, 1975. After 30 years of conflict, Ho Chi Minh’s vision of a united, communist Vietnam had been realized.