1 ATF was based in a rubber plantation at Nui Dat, 8 kilometres (5.0 mi) north of Bà Rịa in Phuoc Tuy Province and consisted of two and later three infantry battalions, with armour, aviation, engineers and artillery support.

Whereas the Americans relied on massed firepower and mobility in big-unit search and destroy operations as part of a war of attrition which often resulted in heavy casualties on both sides, the Australians—although not eschewing conventional operations—emphasised deliberate patrolling using dispersed companies supported by artillery, armored personnel carriers and helicopters to separate the Vietcong (VC) from the population in the villages, while slowly extending government control.

[3][4] Consequently, 1 ATF which would be allocated its own Tactical Area of Responsibility (TAOR) in Phuoc Tuy Province, thereby allowing the Australians to pursue operations more independently using their own methods.

This would allow the force greater freedom of action and the chance to demonstrate the Australian Army's evolving concept for counterinsurgency warfare, developed in part from its operations during the Malayan Emergency.

[13] Its principal objective was to secure Route 15 for military movement to ensure allied control of the port at Vung Tau, while politically it sought to extend government authority in Phuoc Tuy.

[15] Situated on Route 2, Wilton had selected Nui Dat because its central position offered short lines of communication, it was close but not adjacent to the main population centres, and would allow 1 ATF to disrupt VC activity in the area.

[8] Astride a major communist transit and resupply route, it was close to a VC base area yet near enough to Ba Ria to afford security to the provincial capital and facilitate liaison with the local authorities.

[18] 1 ATF would then focus on destroying VC forces in the province, while security of the towns and villages remained a South Vietnamese responsibility.

Few of its senior personnel had direct experience of counter-insurgency operations, and even less a first-hand understanding of the situation in Vietnam, while it had been unable to train together before departure.

[5] From 17 May to 15 June, US and Australian forces secured the area around Nui Dat during Operation Hardihood, deploying two battalions of the US 173rd Airborne Brigade and an element of 1 RAR.

[25] 5 RAR deployed from Vung Tau the same day and was tasked with clearing any VC found in an area 6,000 metres (6,600 yd) east and north-east of Nui Dat.

[25] The plan to operate independently resulted in significant self-protection requirements and 1 ATF's initial priorities were to establish a base and ensure its own security.

[27] Meanwhile, Wilton's decision to occupy Nui Dat rather than co-locate 1 ATF with its logistic support at Vung Tau allowed the task force to have a greater impact, but resulted in additional manpower demands to secure the base.

[16] Indeed, the security requirements of an understrength brigade in an area of strong VC activity utilised up to half the force, limiting its freedom of action.

[29][30] At the Battle of Long Tan on 18 August 1966, D Company 6 RAR with considerable artillery support held off and defeated a VC force of at least regimental strength.

[5] A decisive Australian victory, Long Tan proved a major local setback for the VC, indefinitely forestalling an imminent movement against Nui Dat.

[5][31][Note 1] The battle established the task force's dominance over the province, and allowed it to pursue operations to restore government authority.

[33] Regardless, during February 1967 the Australians suffered their heaviest casualties in the war to that point, losing 16 men killed and 55 wounded in a single week, the bulk during Operation Bribie.

[36] What would ultimately prove to be a tactical blunder by 1 ATF Command and account for the majority of Australian and New Zealand casualties throughout the war, was the laying of a minefield over a 10 km area from Dat Do to the coast.

By June 1967, close to 23,000 "jumping jack" mines had been laid by the Australian engineers within a 100-metre-wide strip of cleared ground between a double row of fences.

[42] At its height 1 ATF numbered over 8,000 men, including three infantry battalions, armour, artillery, engineers, logistics and aviation units in support.

[43] 1 ATF was subsequently deployed astride infiltration routes leading to Saigon in order to interdict communist movement against the capital as part of Operation Coburg during the 1968 Tet Offensive and later during the Battle of Coral–Balmoral in May and June 1968.

At Fire Support Bases Coral and Balmoral the Australians had clashed with regular People's Army of Vietnam (PAVN) and VC main force units operating in battalion and regimental strength for the first time in near conventional warfare, ultimately fighting their largest, most hazardous and most sustained battle of the war.

A Company scaled the mountains, having to make their way through a 200-metre-wide minefield of improvised mines made from unexploded U.S Air Force cluster bombs.

On 19 December, V Company discovered the major part of the hospital, a 200-bed complex complete with underground pharmacy, operating pits and convalescing wards.

As a consequence of the overall US strategy of Vietnamization and with the Australian government keen to reduce its own commitment to the war, 8 RAR was not replaced at the end of its tour of duty.

[58] Although 1 ATF had been able to dominate its area of operations and successfully reduced the PAVN/VC's ability to "influence and coerce" the population of the province, while affording the South Vietnamese government some degree of control, this did not last following their withdrawal, and PAVN/VC forces began to move back into Phuoc Tuy following their departure.