By DAVID BARSTOW, WILLIAM J. BROAD and JEFF GERTH
New York Times

Published: October 3, 2004

This article was reported by David Barstow, William J. Broad and Jeff Gerth, and was written by Mr. Barstow.

In 2002, at a crucial juncture on the path to war, senior members of the Bush administration gave a series of speeches and interviews in which they asserted that Saddam Hussein was rebuilding his nuclear weapons program.

In a speech to veterans that August, Vice President Dick Cheney said Mr. Hussein could have an atomic bomb "fairly soon." The next month, Mr. Cheney told a group of Wyoming Republicans the United States had "irrefutable evidence" - thousands of tubes made of high-strength aluminum, tubes that the Bush administration said were destined for clandestine Iraqi uranium centrifuges, before some were seized at the behest of the United States.

The tubes quickly became a critical exhibit in the administration's brief against Iraq. As the only physical evidence the United States could brandish of Mr. Hussein's revived nuclear ambitions, they gave credibility to the apocalyptic imagery invoked by President Bush and his advisers. The tubes were "only really suited for nuclear weapons programs," Condoleezza Rice, the president's national security adviser, asserted on CNN on Sept. 8, 2002. "We don't want the smoking gun to be a mushroom cloud."

Before Ms. Rice made those remarks, though, she was aware that the government's foremost nuclear experts had concluded that the tubes were most likely not for nuclear weapons at all, an examination by The New York Times has found. Months before, her staff had been told that these experts, at the Energy Department, believed the tubes were probably intended for small artillery rockets.