WASHINGTON - With its claim that Iraq was hiding chemical, biological and nuclear weapons still unproven, the Bush administration is preparing to dispatch hundreds of additional investigators to step up the search - and warning that it might take as long as a year to complete.
The Pentagon is assembling a new "Survey Group" with more than 1,000 experts to interrogate Iraqi scientists and sift through recovered documents to broaden the search for weapons of mass destruction, officials said.
U.S. military units in Iraq have found no prohibited weapons since they invaded the country last month, although they have found gas masks, protective gear and antidote kits.
Some experts, both inside and outside the U.S. government, say Iraq's weapons programs might turn out to be significantly smaller than the Bush administration has portrayed. And some warn that missteps in military units' initial searches of suspected weapons sites unwittingly might have destroyed useful evidence.
But administration officials say they are still certain that the regime of Saddam Hussein was developing and hiding weapons of mass destruction, and that the evidence will turn up eventually. The U.S. contention that Hussein was holding chemical and biological weapons, and that he might give some of them to terrorists, was the administration's principal rationale for going to war.
"We are quite confident of our intelligence," U.S. Secretary of State Colin L. Powell said in a television interview last week. "When the searching is all over and the evidence comes forward, this conflict will rest on a solid foundation of fact."
But officials also have begun an effort to lower public expectations, emphasizing how difficult it will be to find the evidence, and how long it may take for the weapons to be found.
"It is not like a treasure hunt where you just run around looking everywhere, hoping you find something," U.S. Defense Secretary Donald H. Rumsfeld said last week. "The [United Nations] inspectors didn't find anything, and I doubt that we will. What we will do is find the people who will tell us."
"It's going to take time to find anything because ... they buried things, they used underground tunnels ... [and] they took the documentation," Rumsfeld said.
Army Gen. Tommy Franks, head of U.S. Central Command, said recently that the weapons search could take as long as a year.
Officials maintain that they are not frustrated or disappointed that evidence of their principal charge against Hussein has not yet turned up, but they acknowledge that they will face increasing skepticism from critics of the war the longer it takes.
The issue will be addressed this week in the U.N. Security Council, which has summoned chief U.N. arms inspector Hans Blix to report on the situation. Blix clashed with the Bush administration before the war when he argued that his inspections should be allowed to continue; since the war, he has noted acerbically that the United States has found no more evidence of Iraqi weapons than he did.
Blix said last week that he was ready to put a team of U.N. inspectors back in Iraq within two weeks. "I think that the world would like to have a credible report on the absence or eradication of the program of weapons of mass destruction," he told the British Broadcasting Corp.
The Bush administration says it is "too early" for U.N. inspectors to return to Iraq, and expresses little interest in Blix's services. "This seems to be the week of voluntarism ... on the part of people who say they are willing to help get rid of Iraqi weapons, weapons that they weren't willing to admit were there before," a senior U.S. official said.
The administration isn't worried that critics might not find U.S. discoveries credible without international monitors on the scene, the official said. "There will always be people who believe we never landed on the moon," he said. "Besides, it won't just be Americans. There will be Iraqi scientists talking about what they did, too."
A former U.N. inspector who asked not to be identified was sharply critical of the U.S. effort so far.
"Basically, they're making some of the same mistakes we made at the start of the inspections in 1991," he said.
"They're destroying things without understanding what it is and how it got there," he said.
Officials said the Survey Group's effort will rely heavily on Iraqi scientists to lead them to evidence of clandestine weapons programs.
Rumsfeld announced last week that the United States would pay rewards to anyone providing information about weapons of mass destruction.
Iraqi scientists who don't cooperate might be taken to a detention facility for interrogation and ultimately could be charged with war crimes, U.S. officials said.