 From early April 1965 , Ubon became an important base for United States Air Force ( USAF ) attacks on North Vietnam during the Vietnam War , and No. 79 Squadron became part of an integrated air defence system controlled by the USAF on 25 June . This changed the status of the squadron 's presence in Thailand , and RAAF Headquarters assessed that the North Vietnamese would be justified in regarding it as forming part of the air campaign against their country . Due to the threat of counter @-@ attacks on Ubon , the base 's ground defences were upgraded during 1966 ; this included the construction of defensive positions for No. 79 Squadron 's aircraft and personnel as well as the deployment of a detachment of RAAF airfield defence guards . While the squadron did not play an active role in the war , it supported the US effort by providing air defence for Ubon and taking part in exercises with USAF aircraft in which the Sabres adopted tactics used by North Vietnamese MiG @-@ 17 fighters . In December 1965 the commander of the United States Pacific Air Forces , General Hunter Harris , Jr . , wrote to the chief of the RAAF , Air Marshal Alister Murdoch , to suggest that No. 79 Squadron join the USAF operations against the Ho Chi Minh trail in southern Laos which were being covertly conducted by Ubon @-@ based aircraft . The Thai Government indicated that it would allow the squadron to be used for this purpose as long as the Australian operations were conducted without a formal agreement or any public announcement . On 2 March 1966 the Australian Cabinet decided to reinforce the Army and RAAF force in South Vietnam , but rejected the option of expanding the scope of RAAF operations in Thailand . This decision was made on the grounds that the expanded force in South Vietnam and existing deployments to Thailand , Malaysia and Singapore represented the maximum forces Australia could commit to the region . 
