Lessons from Cambodia’s Paris Peace Agreement 30 years on

Cambodia peace agreement

Online and in-person
Australian Institute of International Affairs
32 Thesiger Ct
Deakin ACT 2600


This year marks the 30th anniversary of the Paris Peace Agreement on Cambodia. The agreement, and the subsequent work of the United Nations Transitional Authority on Cambodia (UNTAC), brought an end to the wars which had beset the former Indochina since 1946, enabling Southeast Asia to enjoy significant regional stability for the first time since World War Two.

Two Australians who had vital roles in the Cambodia Peace Process were Mr Michael Costello AO, who was the Australian negotiator in the complex diplomatic work which led to the Paris Agreements, and Lieutenant-General John Sanderson AC, who was the commander of the 16,000 strong UNTAC military contingent.

Michael Costello subsequently became Secretary of the Department of Foreign Affairs and John Sanderson became Chief of Army and Governor of Western Australia.

Asialink and the Australian Institute of International Affairs (AIIA) are pleased to invite Michael Costello and John Sanderson to give their personal reflections on the Cambodia peace process: how the players got there, how the agreement was made to work, how it looks 30 years later, and what they learnt from it.


Michael Costello AO joined the Department of Foreign Affairs in 1971, and worked initially in the Legal and Treaties section on international legal issues relating to law of the sea and French nuclear testing. After postings in Belgrade and Stockholm he was deputy-head of current intelligence at ONA. Costello worked as chief of staff to Hon. Bill Hayden as opposition leader and Minister for Foreign Affairs, where he helped shift Australia to a constructively independent position within the Australia-US Alliance. He stimulated interest in improved relations with the Soviet Union with the onset of Soviet President Mikhail Gorbachev’s glasnost and perestroika policies, and personally negotiated the Human Contacts Agreement – the only bilateral agreement ever made by the Soviet Union which provided for the emigration of Soviet Jews.

Costello returned to DFA in 1987, leading the design for its integration with the Department of Trade to become DFAT. He brokered the Cambodian Peace Agreement and secured the breakthrough which led to the conclusion of the Chemical Weapons Convention after a protracted impasse. Costello served as Secretary of the Department of Industrial Relations (1991-1993) where he devised and implemented policy and legislation modernising Australia’s industrial relations system, moving it to productivity-focused enterprise bargaining using certified agreements. Costello served as Secretary of DFAT (1993-1996) during a fundamental realignment of the world order with the collapse of the Soviet Union, emergence of China, and rapid growth of Asia. He was personally involved in the creation of the APEC Leaders Meeting, establishment of the ASEAN Regional Forum and other innovative diplomatic structures engaging Australia with the world. Costello was head of strategy and then deputy chief executive at the ASX (1996-1999), and then became chief of staff to opposition leader Hon Kim Beazley. He worked in the utilities and energy sector (2003-2018) as CEO of ACTEW Corporation and later CEO of ActewAGL, responsible for the national capital’s water, gas and electricity networks and supply.

In October 2005 Lieutenant General John Sanderson retired after five years in the position of Governor of Western Australia, the state where he was born in 1940. For most of the preceding 40 years he was engaged at the operational and strategic levels of defence and security planning. General Sanderson was Chief of the Australian Army 1995-1998.

During his military career he commanded at all levels including on operational service in Borneo, Vietnam and Cambodia. From the beginning of 1992 until October 1993 he commanded 16,000 soldiers from 34 nations making up the United Nations Peacekeeping Force (UNTAC) during the period of UN controlled transition to peace and free elections in Cambodia. His successful efforts to build the civil/military relationships required for this complex undertaking are widely recognized as ground breaking.

General Sanderson has had a long-term interest in the philosophy and the practical dimensions of international intervention and is extensively published on these subjects. He has lectured on the subject of peace building at many institutions and has been a strong advocate of human rights as the basis of national and international reconciliation. He has been an adviser on their relationship with Aboriginal people to both the Carpenter and Barnett governments in Western Australia, in the latter instance as Chairman of the Indigenous Implementation Board.

His services have been recognized by the award of Member of the Order of Australia (1984), Officer of the Order (1991), Companion of the Order (1994), The United States of America Legion of Merit (Commander Class) and the Grand Cross of the Royal Cambodian Order (2006). He is a graduate of the Royal Military College Duntroon, the Royal Melbourne Institute of Technology, the Australian Staff College, the Joint Services Staff College and the United States Army War College. A civil engineer by background, he is an Honorary Fellow of Engineers Australia, a Fellow of the Australian Institute of International Affairs and holds honorary doctorates from a number of universities.

Please visit the AIIA site for more information.