Geraldine Doogue is civilian patron of the Australian Peacekeeping Memorial Project. She presents ABC RN's 'Saturday Extra' and ABC1's 'Compass' programs. Part 1 of this series here; part 2 here

The UN Transitional Authority in Cambodia (UNTAC), led by Australian Lieutenant General John Sanderson (later Governor of Western Australia), took over the running of Cambodia after years of civil war. UNTAC's job was to rehabilitate the country, run elections (as opposed to just observing them), safeguard human rights and begin economic and psychological rehabilitation, all in a country with almost unimaginable levels of violence.

Retired General Mike Smith, Director of the Security Sector Advisory & Coordination Division in the UN Support Mission in Libya, highlights the importance of John Sanderson's leadership for many of the successes achieved in Cambodia. However, ultimately the job was left undone when the UN decided it was time to go.

August 1992: Members of the Royal Australian Corps of Military Police serving with UNTAC in Cambodia look for stolen equipment in local shops and markets. Photo by Wayne Ryan, courtesy of the Australian War Memorial (Photo ID:CAMUN/92/038/03).

'UNTAC left unfinished business behind', says Smith. 'No provision had been made for the disarmament, demobilisation and reintegration of the three coalition armies. No plan was evident for the creation of a viable defence force, and the Khmer Rouge was able to become more active.'

Cambodia served as a valuable lesson in the evolution of peacekeeping. The importance of staying around for rebuilding long after the first burst of 'peace' is achieved became clear to many. Smith says seeing Cambodia after UNTAC made him determined that if he could make changes in peacekeeping process, he would. 'I knew that if ever I was in a position of authority I would ensure that such practices were not repeated. Years later in East Timor, I remained conscious of this lesson.'

The change in peacekeeping activities from concentrating on inter-state to intra-state conflict, like Cambodia, has been profound. Peacekeepers now deal with conflict that isn't limited to controlling a known zone around borders, with identifiable combatants. Intra-state conflict is constant, erupting everywhere. Civilians are displaced within their own country, by their own countrymen. When a society is torn apart like this, from within, an extraordinary level of anxiety, fear, lawlessness and terror pervades communities and people. It can seem uncontrollable. It certainly produces despair, which peacekeepers encounter and need to counter in themselves at times and in those they serve.

Modern peacekeeping has changed because modern warfare has changed. No longer is the battle the finish of things. It was US Marine General Charles Krulak who first described the difficulty of modern 'three-block warfare', in which soldiers must be trained to fight but must also know how to keep peace, keep combatants apart, prevent further conflict and then help create the conditions in which lasting peace can be built.

This requires our men and women on the ground to work with locals and civilian authorities to rebuild ravaged and exhausted communities through battles that are not ours and to explicitly define what a functioning society might look like. Clearly this takes soldiers and police beyond traditional training.

Prime Minister Julia Gillard, in her anniversary message to peacekeepers, wrote of her gratitude 'that our nation is served by men and women of such courage and compassion, who continue to make the world a better place.'

But the daily dramas of constructive peacekeeping are not the stuff of evening news bulletins. Heroes don't emerge in the same emotionally satisfying way. Goodies and baddies are harder to identify. The achievements are slowly-built competence in the communities concerned, results that hopefully keep them off the front pages. Our gratitude is thus muted.

So the challenge is finding a narrative around peacekeeping that ensures peacekeepers find their place in the popular imagination, equal to the sacrifices and conscientiousness they bring to bear on this noble work.

Additional research by Sophie Townsend.