Former prime minister Mahathir Mohamad opened a peace forum in Kuala Lumpur today with an assertion that the world may be in the throes of a new global conflict.

"Many of us here believe that the fourth world war is already here," he said at the start of a conference which is the latest in a series organised by the veteran politician who stood down as leader in 2003.

"The use of nuclear weapons may very well divide the world into two - a fourth world war is going on now," he said, referring to the two great wars and the Cold War which ended with the collapse of Russia.

"We need to work in the long-term for war to be made a crime. People who wage war should be treated as criminals," he told reporters.

The three-day conference brings together two former UN assistant secretary-generals Denis Halliday and Hans von Sponeck as well as other prominent commentators on global affairs, who all warned against a US attack on Iran.

"This is a real moment of danger. Confrontation is in the making," said von Sponeck, adding that the prospect of a conflict with Iran was an "insane idea" that would be a "a massive failure with a lot of death and destruction."

Cannot function that way

Halliday said the five permanent members of the UN Security Council were compromised by the fact they manufacture 85 percent of the world's weaponry.

"They are the guardians of peaceful security but their economies thrive due to the manufacture of weapons, including nuclear weapons which is the issue perhaps we're facing vis a vis Iran," he said.

Halliday said that the UN charter stated clearly that force should not be used or threatened against a member state to resolve a dispute, and the US actions were threatening the organisation's viability.

"Now, Mr Bush needs to hear this message. The United States needs to understand that the United Nations without respect for international law simply cannot function," he said.

"And it's now reached a point of low credibility that that I think we've never seen before. It's a very endangered organisation", Haliday added.