Following the Australian withdrawal from Vietnam the national defence strategy changed from forward defence through stationing military units in South East Asia to the defence of continental Australia. In line with this shift, the Australian military began to explore new ways of patrolling the Australian coastline. In the late 1970s the Special Air Service Regiment conducted a number of exercises in northern Western Australia which aimed to assess the ability of unconventional units to patrol the long and sparsely populated coastline of northern Australia. These trials indicated that recce patrols, operating in much the same way as an SAS patrol could provide a very useful capability.