The US task force directing the search for Iraq’s WMD likely will return home next month without discovering chemical, biological or nuclear materials. This failure could do great harm to the credibility of the Bush administration and the integrity of the US intelligence community.

Many reasons have been offered for the failure of US weapons experts and scientists to find a trace of nonconventional weapons in Iraq. Israeli intelligence sources claimed these weapons had been moved to Syria before the war began, but US intelligence agencies never believed it.

US sources claimed that the Iraqis destroyed vast stocks of WMD before the war, but sophisticated collection technology would have discovered traces of such activity and US inspectors would have located the detritus of a massive destruction effort. It’s possible that the Iraqis could have hidden or deeply buried sensitive materials, but even the leaders of WMD hunters from Task Force 75 and a special operations group from the Defense Threat Reduction Agency don’t believe such a theory.

As a result, these teams are now searching for evidence of Saddam Hussein’s crimes against humanity, Iraqi covert actions abroad and even the theft of Jewish antiquities from Iraqi museums — a far cry from the artifacts of WMD.

If the claims of President Bush, Secretary of State Colin L. Powell and CIA Director George J. Tenet to justify the war were vastly exaggerated or simply false, there will be significant consequences.

For one, the distortion of evidence of Iraqi WMD will make it harder to gain international cooperation in the war against terrorism and the campaign to prevent the spread of WMD.

These efforts require international assistance. Information from foreign intelligence services has been required in the arrest or capture of all suspected Al-Qaeda terrorists thus far. Any success in stopping the strategic weapons programs of Iran and North Korea, both more advanced than those of prewar Iraq, will require international help.

Any misuse of intelligence by the White House or politicization of intelligence by the CIA weakens the key instrument in preventing further acts of terrorism and thus undermines US national security interests.

The misuse of intelligence during the Vietnam War prolonged a brutal and costly conflict. The manipulation of intelligence during the Iran-Contra affair in the 1980s led to political embarrassment for the Reagan administration. The use of intelligence for the political ends of any administration is simply unacceptable.

Finally, the worst possible scenario for the security interests of the United States and the international community would be ending the inspections too early and then learning about the possible looting or smuggling of any strategic materials from Iraqi weapons sites.

As White House spokesman Ari Fleischer noted two months ago: “(WMD) is what this war was about and is about. And we have high confidence it will be found.’’ We must now make sure that the hundreds of weapons sites were not looted of detritus, which can only be done with an intensified international inspection effort.

The United States must take immediate steps to regain credibility at home and abroad. Since chief UN weapons inspector Hans Blix does not officially retire from his position until next month, it is not too late to invite experienced UN weapons inspectors to scour Iraq and thus gain international acceptance of any findings.

In addition to improving US credibility, international inspectors would make it easier to interview Iraqi experts and find needed documents and evidence.

The Senate Intelligence Committee or the inspector general of the CIA must scrutinize the findings of the intelligence community on Iraqi WMD, especially those estimates prepared after the terrorist attacks of Sept. 11, to determine whether intelligence was politicized to support the political agenda of the Bush administration.

The administration has dragged its heels over an independent inspection of 9/11 and prevented the release of the 9/11 joint congressional inquiry, but it must not block the efforts of the Senate panel or the CIA to determine whether the intelligence community actually accommodated political interests. There is too much at stake to delay these two essential steps.