If Saddam Hussein had few or no weapons of mass destruction, why did he act as if he possessed arsenals of them? Why did Iraqis harass U.N. inspectors, bar their entry into certain buildings and sneak trucks out the back gates of compounds if there was nothing to hide?

Analysts have been quick to suggest reasons. A prevailing view is machismo -- Hussein was trying to conceal his weakness, not his strength. Some experts, such as former weapons inspector David Kay, have said that scientists, seeking to enrich themselves with funds for phony projects, hoodwinked Hussein, not the inspectors.

But one factor, just as important as the others, has been overlooked. U.N. inspections were undercut from the start by U.S. policy.

American officials boasted continually that the United States would never allow the United Nations to lift economic sanctions, imposed after the Persian Gulf War, as long as Hussein remained in power. As a result, Hussein never had much incentive to cooperate with the inspectors. If the U.S. carried out its threat, sanctions would remain no matter what he did.

The United States corrupted the process of inspection.

Barely two months after the Gulf War ended in 1991, deputy national security advisor Robert M. Gates, speaking on behalf of the George H.W. Bush administration, told the American Newspaper Publishers Assn. that “Saddam is discredited and cannot be redeemed. His leadership will never be accepted by the world community and, therefore, Iraqis will pay the price while he remains in office. All possible sanctions will be maintained until he is gone. Any easing of sanctions will be considered only when there is a new government.”

The speech surprised and upset the mission of U.S. Ambassador Thomas R. Pickering at the U.N. He had steered through the Security Council the war-ending resolution, a document so long that ambassadors, borrowing a favorite phrase of Hussein’s, dubbed it “the mother of all resolutions.” The resolution contained no demand that Iraq rid itself of Hussein. Instead, its key provisions set up a system of U.N. inspections, demanded the elimination of all Iraqi WMD and pledged to keep sanctions in place until inspectors verified this outcome. Sanctions prohibited any country from buying Iraqi oil and other products; Iraq could purchase only medicine and food abroad.

“The United States has been punctilious about staying within the resolutions up to now,” a disappointed aide to Pickering told me after hearing about the Gates threat. “In general, it [the threat] goes beyond the resolution.”

The Clinton administration continued the policy in a somewhat different form. As Secretary of State Madeleine Albright said in a speech at Georgetown University in 1997: “We do not agree with nations who argue that if Iraq complies with its obligations concerning weapons of mass destruction, sanctions should be lifted. Our view, which is unshakeable, is that Iraq must prove its peaceful intentions. It can only do that by complying with all the Security Council resolutions to which it is subject. Is it possible to conceive of such a government under Saddam Hussein? ... The evidence is overwhelming that Saddam Hussein’s intentions will never be peaceful.”

Albright’s speech should not have been a surprise. It repeated a policy she had spelled out when she was U.N. ambassador earlier in the Clinton administration. Her reference to “all the Security Council resolutions” recalled that the U.N., aside from ordering the elimination of WMD, had demanded that Iraq accept an Iraq-Kuwait boundary worked out by a demarcation commission, account for all missing Kuwaitis and pay compensation to all nations and individuals financially hurt by the war. By linking the lifting of sanctions to all these resolutions, the Clinton administration was placing what it hoped was an impossible burden on Hussein, or at least one that he would regard as intolerable. In her recently published memoirs, Albright described the policy as only “a slightly different approach” from that of the first Bush administration.

Despite this, Richard Butler, the Australian diplomat who led the U.N. inspectors, was surprised by Albright’s Georgetown speech. In “The Greatest Threat,” his book about dealing with the Iraqis, he insisted that Hussein “could [have achieved] sanctions relief at any time by giving up his weapons.” Though the Albright speech, in Butler’s view, “somewhat muddied” the issue of sanctions, he didn’t regard it as a definitive statement of U.S. policy.

Butler writes that after talking with Bill Richardson, Albright’s successor as U.S. ambassador to the U.N., he was authorized to tell Iraqi Deputy Prime Minister Tarik Aziz in Baghdad in 1998, “I have consulted with the U.S. government on this matter at the Cabinet level, and I am absolutely satisfied that once the disarmament work is completed, there will be no impediment to the lifting of sanctions.” That would have been small consolation to Iraq in the absence of any public statement by Albright changing U.S. policy.

Butler’s meeting with Aziz was testy and bitter, perhaps because Aziz grasped American intentions better than Butler. “You understand, Mr. Butler, that the government is working with the Special Commission [the U.N. inspectors] in order to get sanctions lifted,” Aziz said. “If there is no prospect of this happening, why should we continue to cooperate? We are ready to face the consequences, including war. Tell the Security Council I said so.”

Yet the situation was ambiguous enough for the Iraqis to show some cooperation from time to time. By the mid-1990s, France and Russia were openly lobbying for the end of sanctions. If the inspectors ever declared Iraq free of the prohibited weapons, the Iraqis reasoned, perhaps France and Russia could persuade the United States to relent. Moreover, U.N. Secretary-General Kofi Annan, after his controversial meeting with Hussein in 1998, signed a joint memorandum with Aziz in which he “undertook to bring this matter [the lifting of sanctions] to the full attention of the members of the Security Council.” Perhaps Annan could use his international prestige and moral force to persuade the United States to change its policy.

Would the United States have backed down? Probably not. Albright had pronounced U.S. policy “unshakeable.” Toughness toward Iraq had become one of her trademarks. The chances were high that the United States would veto any attempt by other Security Council members to lift sanctions no matter what the inspectors reported.

We still don’t know what motivated continued Iraqi intransigence that led to the U.S bombing and suspension of inspections in 1998.

But Iraqi frustration with U.S. policy may have been a significant factor in the decision by Iraqi officials, representing a weak and humiliated government, to preen and bluster and stand in the way of Butler -- foolish and dangerous behavior that bolstered the view that the Iraqis had a lot to hide. When the new presidential commission investigates the flawed intelligence about Hussein’s WMD, it should not overlook the U.S. role in the subversion of inspections.

When the George W. Bush administration took office in 2001, there were no longer any inspectors in Iraq. Intelligence analysts, who believed that Hussein had concealed his WMD programs during inspections, assumed he surely must be expanding them now. The lifting of sanctions became a moot issue.

The new issue was war. By the time U.N. inspectors returned in late 2002, the Iraqis, fearful of a U.S. invasion, cooperated more than they ever had. Resolution 1441 -- the Security Council resolution that served as President Bush’s legal justification for war -- did not even mention sanctions. Instead, it declared Iraq “in material breach” of previous U.N. resolutions and threatened “serious consequences” if Iraq continued to defy the U.N. Their new cooperation did not help the Iraqis. Many Bush aides looked on U.N. inspections with contempt -- a feeble exercise by incompetent inspectors fooled time and again by duplicitous Iraqis. Without waiting for the inspectors to finish their work, Bush ordered the invasion.

In 2003, the Security Council did lift sanctions against Iraq, but, as the George H.W. Bush and Clinton administrations had promised, this came only after the fall of Hussein.

STANLEY MEISLER, AUTHOR OF "UNITED NATIONS: THE FIRST FIFTY YEARS," COVERED THE U.N. FOR THE TIMES IN THE 1990S.