Mr Guehenno, who is stepping down soon after eight years as UN Under Secretary General for Peacekeeping, warned that his successor faces serious challenges and that just one failure among the 20 UN peace missions could wreck global support for all of them.

Although the UN operations have regained credibility after the devastating 1990s failure in former Yugoslavia, 'This is a time to have quite serious concerns,' Mr Guehenno said.

'One big failure would be enough to destroy that credibility. ... If it breaks it will take years to rebuild.'

Speaking at Washington's Centre for Strategic and International Studies, Mr Guehenno singled out eight missions facing major challenges: Darfur, Sudan's south, Eritrea and Chad in eastern Africa, Afghanistan, Lebanon, Kosovo and the Democratic Republic of Congo.

All were endangered by the flagging world support to supply funds and troops to the 100,000-strong global UN peacekeeping force.

'Is there enough political will?' to keep up the 20 missions, he asked. 'There is not at the time.'

'Can the major powers focus on so many issues at once? I doubt it.' Mr Guehenno singled out the Darfur mission as being he most at risk, lacking cohesive backing by the major powers, much-needed ground staff and helicopters, and the domestic political will for a settlement.

'The commitment to the political process is uncertain,' he said, citing the lack of a unified view among Sudan's political groups and splits among Darfur's rebels.

He also pointed to the lack of unity among the world powers for the Darfur effort.

China, which has oil interests in Sudan, has been strongly criticised for not pressing the government to stop fighting in the country's impoverished western region.

'It is not a good context to conduct a peacekeeping operation,' Mr Guehenno said.

Fighting intensified over the past year
He said the international effort in Afghanistan, where fighting between an international force and Taleban fighters has intensified over the past year, needs a 'new beginning' with renewed commitment from around the world.

Mr Guehenno announced in March that he would leave his post in June after eight years during which the size of the peacekeeping operations soared and the annual budget grew to some US$7.5 billion (S$10.3 billion).

His yet-unnamed replacement will inherit a tenuous record of successes, in El Salvador, Cambodia, and especially West Africa, where the UN has played a key role in quelling violence in Liberia, Sierra Leone and Ivory Coast, Guehenno said.

He also claimed real but 'still fragile' progress in Africa's Great Lakes region.

'You can judge a peacekeeping success only 10, 15 years later,' he said.

Donor fatigue
Current problems involve fatigue among donors of funds for the operations - mainly the United States, Europe and Japan - as well as the principal risk-bearers, the suppliers of the blue-helmeted UN troops: mostly governments of South Asia, South Africa and Latin America.

'The international community is overstretched,' he said. 'We need to bring more actors to the peacekeeping table.'

Aside from the unstable eastern Africa region, Guehenno pointed to the political risks to missions in Lebanon and Kosovo, due to political disagreement both internally and internationally.

'A political process is not something that can be coerced,' he said. 'When you deploy peacekeeping operations, you need to have a peace to keep,' he said.

'That's what we learned the hard way in Yugoslavia.' -- AFP