nine additional US battalions, or 14,000 troops, to bring the total in Vietnam to 13. Allied nations of the Free World Military Forces were expected to contribute another four battalions. Westmoreland planned to develop a series of defensive positions around Saigon before expanding operations to pacify the South Vietnamese countryside and as a result a number of sites close to Viet Cong dominated areas were subsequently chosen to be developed into semi-permanent divisional-level bases. Such areas included Di An which was intended to become the headquarters of the US 1st Infantry Division, while the US 25th Infantry Division would be based in the vicinity of Cu Chi. However, large-scale military operations to clear the intended base areas had to wait until the dry season. Yet the allied enclave strategy proved only transitory and further setbacks led to additional troop increases to halt the losing trend. With the situation reaching a crisis point during the Viet Cong wet season offensive in June 1965, Westmoreland requested further reinforcement and US and allied forces increased to 44 battalions which would be used to directly bolster the ARVN. Australia's growing involvement in Vietnam reflected the American build-up. In 1963, the Australian government had committed a small advisory team, known as the Australian Army Training Team Vietnam (AATTV), to help train the South Vietnamese forces. However, in June 1965 the decision to commit ground troops was made, and the 1st Battalion, Royal Australian Regiment—originally commanded by Lieutenant Colonel Ivan 'Lou' Brumfield—was dispatched. Supporting 1 RAR was the 1 Troop, A Squadron, 4th/19th Prince of Wales's Light Horse equipped with M113 armored personnel carriers, artillery from the 105th Field Battery, Royal Australian Artillery and 161st Battery, Royal New Zealand Artillery, and 161st Reconnaissance Flight operating Cessna 180s and Bell H-13 Sioux light observation helicopters; in total 1,400 personnel. The Australian units and New Zealand artillery were attached to the US 173rd Airborne Brigade under the command of Brigadier General Ellis W. Williamson in Bien Hoa and operated throughout the III Corps Tactical Zone (III CTZ) to help establish the Bien Hoa–Vung Tau enclave. Although logistics and resupply were primarily provided by the Americans, a small logistic unit—1st Australian Logistics Company—was situated at Bien Hoa airbase. Unlike later Australian units that served in Vietnam, which included conscripts, 1 RAR was manned by regular personnel only. Attached to US forces, 1 RAR was primarily employed in search and