The United Nations' Secretary General, Kofi Annan, has signalled the UN is taking a fundamental look at the way it does its work in the wake of the war in Iraq.
Mr Annan said that many people sensed the UN was living through a crisis of the international system and there might be need for radical reform.
Annan: Many member states felt ignored over Iraq
A process of soul-searching has begun about whether multilateralism has a future.
Following a two-day meeting of heads of international regional organisations in New York, Mr Annan said there had been some serious exchanges about the UN Charter and the role played by the Security Council in legitimising the use of international force.
This re-examination had been prompted, said Mr Annan, by the depth and nature of recent crises:
"The war in Iraq, as well as crises such as those in Liberia and the Democratic Republic of the Congo, force us to ask ourselves whether the institutions and methods we are accustomed to are really adequate to deal with all the stresses of the last couple of years, or whether perhaps they are in need of a radical reform..."
Prompting this self-doubt has been the decision by the United States and its allies to go to war in Iraq without the specific backing of the Security Council.
Mr Annan says that many member countries have complained to him that throughout the Council debates preceding the war, their views were ignored and they felt excluded.
Mr Annan says he has no doubt that when the UN General Assembly meets again next September, it will be an occasion for many member states to reassert their belief in the resolution of international issues on a multilateral basis.