WASHINGTON -- The Bush administration's renewed assertions of links between Iraq and Al Qaeda are based largely on the murky case of a one-legged Al Qaeda suspect who was treated in Baghdad after being wounded in the war in Afghanistan.
Jordanian Abu Musab Zarqawi is emerging as a possible linchpin in the White House's efforts to win support for confronting Iraq, a case Secretary of State Colin L. Powell is scheduled to press before the United Nations next week.
U.S. intelligence officials say Zarqawi, 36, is one of Al Qaeda's top leaders in Europe and is allegedly Osama bin Laden's chief of chemical weapons.
His travels to Iraq and his suspected ties to terrorist plots in Britain, France and Spain tantalize White House hawks eager to link two of America's declared enemies and win support from skeptical Europeans for a possible invasion of Iraq.
But even as Powell promised Wednesday to lay out new information on Iraq-Al Qaeda links, U.S. intelligence sources said the Zarqawi connection remained highly circumstantial. Indeed, several sources said there was no clear evidence that Zarqawi's ties to Baghdad were more than medical. He is said to have had a leg amputated in a Baghdad hospital.
"If you're going to try to convince me we should go to war with Saddam Hussein, you shouldn't rest too heavily on" the Zarqawi case, said a congressional source familiar with the intelligence on Iraq and Al Qaeda.
After pressing the case last year that it suspected Iraq-Al Qaeda links, the administration seemed to drop the matter in recent months.
But in a campaign to regain momentum in the diplomatic push for confronting Iraq, the White House has revived those claims of ties to Al Qaeda this week.
President Bush said in his State of the Union address Tuesday evening that "Saddam Hussein aids and protects terrorists, including members of Al Qaeda."
He cited evidence from "intelligence sources, secret communications and statements by people now in custody."
Powell said Wednesday that documenting the ties between Iraq and Al Qaeda will be one of the elements of his appearance at the United Nations, touted by the White House as a presentation of the best evidence it has against Iraq that can be shared with the public.
"We believe, and I will talk to this next week, that there have been links between Al Qaeda and Iraq," Powell said in a television interview Wednesday. "There have been contacts over the years, and there may be Al Qaeda presence in Iraq."
Defense Secretary Donald H. Rumsfeld went further Wednesday, saying that evidence supporting the claims of such links "has grown."
Intelligence officials said they are puzzled by the administration's new push.
"To my knowledge, there's nothing new," said a senior U.S. intelligence official who asked not to be identified. The expectation within the CIA regarding Powell's speech, the source said, "is that it's going to be more comprehensive than bombastic and new."
Intelligence officials have discounted -- if not dismissed -- other information believed to point to possible links between Iraq and Al Qaeda.
The CIA said it can find no evidence supporting post-Sept. 11 reports that Mohamed Atta, one of the hijackers in the attacks, met with an Iraqi agent in the Czech capital, Prague, in 2001.
Similarly, intelligence officials described reports that Hussein is funding an Al Qaeda-connected extremist group in northern Iraq as "wildly overstated."
There is no evidence so far to confirm that Iraq is arming, financing or controlling the group, known as Ansar al-Islam, one official said. "There isn't a factual basis for such assertions," the official said.
Kurdish officials in northern Iraq have told Western intelligence that the group, which controls a tiny Taliban-style fiefdom, has given shelter to Zarqawi. It claims to have amassed stockpiles of ricin, cyanide and aflatoxin, and has vowed to use the substances against American troops if they invade Iraq.
U.S. officials say they cannot confirm that Zarqawi has links to Ansar al-Islam, nor can they confirm published reports that he carried a poisonous substance disguised as an ointment into Turkey.
Zarqawi remains the focus of an international manhunt. He is suspected in a series of European plots, possibly including a recently foiled scheme to poison food at a British military base. The search for Zarqawi led police in Britain to the discovery of a small factory to produce ricin in a London apartment.
Zarqawi also has been tied to recent arrests of suspected terrorists and confiscations of chemicals, equipment and protective gear in France and Spain. Authorities in Jordan suspect he may be involved in the killing of a U.S. foreign aid worker there last year.
Powell's presentation next week is also expected to include imagery from satellites and other sources showing what the White House believes is evidence that Iraq is hiding materials from U.N. weapons inspectors.
Officials said Wednesday that they are increasingly concerned Iraq has penetrated the U.N. team, anticipating visits and moving materials in advance.
"Inspectors have a very difficult time arriving anyplace that it wasn't expected," Rumsfeld said. "They have a very difficult time talking to anybody that hasn't been programmed to talk to them. How that happens, certainly one possibility is penetration."
British officials said that Iraq may be bugging U.N. hotel rooms and that minders have rehearsed ways to block inspectors from reaching sensitive sites. Among the tactics are staged car accidents designed to delay convoys if they get too close to an area where materials are believed to be hidden.
White House officials also acknowledged Wednesday that they are scrambling to assemble a briefing that Powell can present that will help make the case against Iraq without compromising U.S. intelligence methods.
"The question is how much can you declassify?" said one senior administration official.
Staff writers Maggie Farley at the United Nations, Doyle McManus and Robin Wright in Washington and special correspondent William Wallace in London contributed to this report.