While Viet Cong and North Vietnamese military activity in South Vietnam continued at a low level and U.S. forces gradually withdrew, the Republic of Vietnam re-equipped and modernized its armed forces in a program called “Vietnamization.” To meet the VNAF ‘s needs for trained personnel, the USAF in the fall of 1969 began training programs both in South Vietnam and the United States. On December 1, 1969, the AC-47 gunships flew their last combat missions as U.S. aircraft: subsequently, the United States transferred the AC-47s to the VNAF and the Royal Laotian Air Force (RLAF). A few weeks later, on January 22, 1970, the U.S. Air Force began transferring to the VNAF the Tactical Air Control System that handled air defense, tactical attacks, and air traffic control in South Vietnam. On March 15 the USAF inactivated the 37th Tactical Fighter Wing at Phu Cat, an air base on the coast 250 miles northeast of Saigon, and the 12th Tactical Fighter Wing at Cam Ranh
Bay, 180 miles northeast of Saigon. The USAF began withdrawing civil engineering units in April.
The USAF might reduce its forces and operations in South Vietnam, but other events prompted increased U.S. involvement in Laos. On November 1, 1969, with the onset of another dry season. the USAF began another intensive air campaign. COMMANDO HUNT III. in the Laotian panhandle to counter an increasing flow southwards of enemy troops and supplies. The 14th Special Operations Wing's AC-119 and AC-130 gunships. although only flying a small number of the total sorties along the Ho Chi Minh Trail, accounted for almost half of the destroyed or damaged trucks. Meanwhile. tactical air and B-52 aircrews focused on area targets and antiaircraft positions.
While the USAF effort in the Laotian panhandle focused on interdiction. aerial action in northem Lam involved close air support. In January 1970 the Pathet Lao and North Vietnamese mounted a major offensive against Royal Laotian forces. On January 4 the Seventh Air Force sent a helicopter squadron to Long Tieng, an airstrip 100 miles north of Vientiane, for operations around Muong Soui. It also dispatched AC-119K gunships to Udorn Air Base. Thailand. on February 15 to provide armed reconnaissance along major roads in northem Laos and close air support for Laotian forward bases. Two days later. in an effort to slow the enemy advance. the USAF used B—52s against North Vietnamese and Pathet Lao positions in northern Laos. Despite the intense air attacks. the Communist forces captured Muong Soui on Febuary 24 and advancing over the Plain of Jars. by March 17 threatened Long Tieng. The Seventh Air Force helped fly in reinforcements of Thai and Laotian troops to Long Tieng and evacuated refugees, while its tactical aircraft provided close air support to the beleaguered troops. By March 30 the Pathet Lao and North Vietnamese forces once again had retreated. and Long Tieng appeared safe, at least until the next dry season.
‘The North Vietnamese and Viet Cong for many years had used Cambodia as a sanctuary with relative impunity, although the USAF as early as
March 1969 bombed targets in Cambodia with B-52s. Then, in March 1970, a new Cambodian government challenged the Communist military
presence. The Communists reacted with a military campaign against Cambodian forces. As the conflict escalated, on April 20 Cambodian Premier Lon Nol formally sought U.S. aid. On the 24th the USAF began flying tactical missions against enemy targets in Cambodia, and 5 days later, the ARVN entered Cambodia to destroy enemy bases and supplies and assist Cambodian troops fighting the Communists.
