A high-risk mission to Cambodia

After more than two decades of brutal conflict, Cambodia's warring factions had finally agreed on a settlement and Australia was set to play a big part in the ensuing peacekeeping mission.

This was Australia's first major peacekeeping operation of the post-cold war "new world order", when a few unsettled conflicts seemed to be all that stood in the way of a peaceful future for all.

Cabinet papers for 1990 and 1991, released by the National Archives of Australia, show the Hawke Labor government was willing to contribute a substantial force for the new UN Transitional Authority in Cambodia mission.

This was only fair, considering Australia's central role and especially that of then foreign minister Gareth Evans in the diplomacy leading up to the agreement.

Cambodia had been steadily destabilised through its proximity to the war in Vietnam and that led to the ultra-left Khmer Rouge taking over in 1975.

This was a regime of hideous brutality which killed an estimated million Cambodians until it was ousted when Vietnam invaded in 1979.

Vietnam ruled Cambodia for a decade, backed by the USSR but opposed by a coalition of nationalist groups, including the largest, the Khmer Rouge.

In a fairly typical example of Cold War politics, this coalition was supported by China, the US and ASEAN nations with the Khmer Rouge even continuing to occupy Cambodia's seat in the UN.

With the end of the Cold War, Vietnam withdrew but the conflict continued. The Evans proposal was for the Cambodian government and three opposition factions including Khmer Rouge to share power until UN-supervised elections could be held.

At that time Khmer Rouge and government forces were still fighting in the country's north. The UN was to be responsible for the country's administration and security.

The peace agreement was signed in Paris in October 1991. Australia initially contributed personnel to the UN advance mission and to the UNTAC mission, formally approved by the UN in February 1992.

It comprised 500 troops, mostly signallers who provided communications across the country, six Black Hawk helicopters and the UNTAC commander army engineer Lieutenant General John Sanderson.

It was regarded as a high-risk mission with the Office of National Assessments cautioning the government in October 1991 that renewal of fighting, a distinct possibility, could signal the breakdown of the peace settlement and lead to UN withdrawal.

Despite some incidents, it never occurred and the election was held in May 1993. UNTAC withdrew six months later. There were no Australian casualties.

Evans was criticised for involving the blood-drenched Khmer Rouge in the peace process but correctly anticipated that without ongoing Chinese support, it would fade away.

The Khmer Rouge effectively ceased to exist by the end of the decade.