1975 spring offensive

The 1975 spring offensive (Vietnamese: chiến dịch mùa Xuân 1975), officially known as the general offensive and uprising of spring 1975 (Vietnamese: Tổng tiến công và nổi dậy mùa Xuân 1975), was the final North Vietnamese campaign of the Vietnam War that led to the capitulation of South Vietnam. In December 1974, People's Army of Vietnam's (PAVN) forces crossed from their bases in Cambodia and captured Phước Long Province by January 1975. After this success, the North Vietnamese leadership increased the scope of the PAVN offensive and attacked the Central Highlands from Cambodia in March, capturing the city of Buôn Ma Thuột on 18 March. These operations were intended to be preparatory to launching a general offensive in 1976.

Following these defeats, the South Vietnamese leadership realized they were no longer able to defend the entire country and ordered a strategic withdrawal from the Central Highlands. The retreat was a disaster as civilian refugees fled under fire alongside soldiers along a single highway to the coast. This situation was worsened by confusing orders, lack of command, and a well-led and aggressive enemy, which led to the destruction of most South Vietnamese forces in the Central Highlands. A similar collapse occurred in the northern provinces where PAVN forces captured both Huế and Đà Nẵng by the end of March.

Following the ARVN collapse, North Vietnam transferred its northern forces over 350 miles (560 km) south down the Ho Chi Minh trail through Laos and Cambodia to capture the South Vietnamese capital of Saigon and win the war in time to celebrate their late President Ho Chi Minh's birthday. South Vietnamese forces regrouped around the capital and defended the key transportation hubs at Phan Rang and Xuân Lộc, but the South Vietnamese had lost the political and military will to continue. On 21 April, South Vietnamese President Nguyễn Văn Thiệu resigned, hoping the North Vietnamese would reopen negotiations. However, the PAVN continued to attack. While IV Corps southwest of Saigon remained relatively stable, preventing VC units from capturing any provincial capitals, PAVN forces entered Saigon, forcing the South Vietnamese government, now under the leadership of Dương Văn Minh, to surrender on 30 April 1975.