Governments must engage with each other if the world is to move beyond the tragic events of September 11, the prime minister said on Monday.

In a speech to the Lord Mayor's banquet in London's Guildhall, Blair said that isolationism was an obstacle to developing a new world order.

Calling for "a new doctrine of international community" the prime minister said that the lessons of the last few weeks were that an inward-looking approach had no part to play in global affairs.

In a speech dominated by foreign affairs, Blair said that "realpolitik and idealism have come together" creating new opportunities to tackle the deep-rooted issues and differences that lie at the heart of conflicts around the world

He told his audience that there was no conflict between "the self interests of a nation" and the interests of a broader community. After the terror attacks on New York and Washington new "unimaginable'' international alliances had come into being, said the PM, arguing that some good had emerged before from an evil act.

The speech built upon the prime minister's party conference speech in early October in which he stressed that the world as a whole would have to respond to the challenge of defeating terrorism and restoring confidence.