Although receiving little publicity, it is true to say that without the KC-135 tanker force the USAF’s air war in Southeast Asia simply could not have taken place.  The KC-135 was still in the process of replacing the ageing KB-50s and KB-97s in the tanker role when the war began.  Eventually 729 KC-135 tankers were delivered to the USAF, the majority of them originally flying under SAC control.

Clark AB in the Philippines was the first temporary base for KC-135 tankers used in the early months of the war but more permanent bases were needed.  In January 1965 the 4252nd SW was established at Kadena on the island of Okinawa in preparation for the start of Arc Light B-52 raids later in the year.  Forward operating locations were also established at Don Muang and Takhli in Thailand to provide support for tactical aircraft operations under the generic code name of Young Tiger.  By the middle of 1965 there were 45 KC-135s based in the Southeast Asian theatre, the majority of them at Kadena.  Refuelling areas for B-52s from Guam were situated near the northern tip of the Philippines while those for tactical aircraft were sited over Thailand, Laos and the Gulf of Tonkin.  Occasionally, in cases of dire emergency, tankers would even cross the border to refuel aircraft over North Vietnam itself, although the risks of SAMs and MiGs made this a risky business.

To satisfy the ever-increasing requirement for more tanker support, more KC-135s started operations from Takhli in August 1966.  By the end of the year there was a total of 75 KC-135s based in Southeast Asia.  However, the basing of tankers at Takhli was not enough and a new airfield at Ching Chuan Kang on the Chinese Nationalist island of Taiwan was constructed to take KC-135s as well as a C-130 wing.  Due to various delays in construction the first tankers did not move in to CCK, as it was invariably known, until February 1968.

In 1972 the number of KC-135s deployed to Southeast Asia began to swell as the tempo of the air war increased.  By the end of June there were 60 KC-135s at Kadena with 46 at U-Tapao, 28 at Clark, 20 at Takhli, 13 at Don Muang and seven at Korat.  Of the nominal total of 172 KC-135s available, 114 were earmarked for Young Tiger tactical missions and 58 for Arc Light and other strategic missions.  September 1972 was the peak month of the war for tanker activity with a total of 2,661 Young Tiger and 1,241 Arc Light sorties being flown.  These 3,902 sorties involved the transfer of 159.6 million pounds of fuel in 12,509 refuellings.

In addition to supporting combat missions over Southeast Asia, tankers also made possible the rapid deployment of aircraft to the theatre from the USA, especially in 1972 when a large number of deployments were made.  Bullet Shot deployments involved the move of B-52s to Andersen and KC-135s to U-Tapao and Kadena while a series of Constant Guard deployments brought in a number of A-7D, F-111 and F-4E units while redeploying other units that were displaced by the newer aircraft.

From June 1964 to August 1973 USAF tankers flew a total of 194,687 sorties in support of missions in Southeast Asia.  During these sorties the aircraft made 813,878 refuellings and transferred a grand total of 8,963,700,000lbs of fuel, which equates to about 1.4 billion gallons.

In addition to the three KC-135s lost in Southeast Asia in 1968 and 1969, one other aircraft should be mentioned, as it was lost in connection with the war.  On 24 September 1968 KC-135A 55-3133 of the 509 BW, attached to the 4258 SW, was returning SAC personnel from the war zone to the USA when it suffered an engine failure over the Pacific.  The aircraft diverted to Wake Island but crashed during a missed approach killing 11 of the 52 on board.  The accident was due to the failure to retract the spoilers (which had been deployed during the descent) during the overshoot.