In his first major speech on foreign affairs, Iain Duncan Smith yesterday launched a wide-ranging attack on Tony Blair's vision of a "new world order" in the wake of last September's terrorist attacks on the US.

"Today's utopian internationalists, who only have to glance at an opportunity for multilateral intervention in order to jump at it, run the risk of weakening national support for those military engagements which are fundamental to our security," he said.

Blair said he was "astonished" by the remarks. "This idea that somehow we isolate ourselves from the rest of the world, we draw in upon ourselves, that Britain becomes a sort of reclusive figure trying to shield ourselves from what happens on the international stage - that is so wrong and misguided," said the prime minister.