Iraq victory ? Not possible says Kissinger

But Kissinger, an architect of the Vietnam War who has also advised Bush on Iraq, warned that a sudden pullout of US troops or loss of influence could unleash chaos.

"I am basically sympathetic to President Bush," he said. "I am partly sympathetic to it because I have seen comparable situations."

During his tenure under President Richard Nixon, first as national security adviser and then as secretary of state, Kissinger faced a similar challenge in formulating policy for a Vietnam War that was increasingly unpopular at home.