1973: LAST SEA COMBAT MISSION/VIETNAM SUMMARY. All US bombing in Cambodia ends after eight years of conventional operations. An A-7D from the 354th TFW flies the last combat mission. Altogether, USAF flies in the war 5.25 million sorties over South Vietnam, North Vietnam, northern and southern Laos, and Cambodia, between the US, forward bases, and bases in the Far East and Southeast Asia.