One by one, the rationales for the invasion and occupation of Iraq are falling away. Administration postulations of a grave and gathering Iraqi WMD threat and of a Saddam-Osama alliance dedicated to visiting a nuclear 9/11 on the United States have evaporated in the absence of discovered WMD. The same holds for an alleged collaborative relationship between Iraq and al-Qaeda and Saddam’s complicity in 9/11. There is, indeed, no there there.

The claims that regime change in Iraq would also deal a body blow to Islamic terrorism and set the stage for the Middle East’s transformation from autocracy to democracy are also belied by the facts. The Islamic terrorist threat has actually increased in the wake of Operation Iraqi Freedom (OIF), in large part because the Anglo-American occupation of an Arab heartland has not only stimulated recruitment of terrorists but also provided them with a new set of targets. As for democracy, the nature of future governance in Iraq remains far from clear (assuming the country does not collapse into civil war), and there are few signs that autocracy is on the run in countries like Saudi Arabia, Egypt, and Syria.

OIF certainly has not cowed Iran and North Korea from pursuing their nuclear weapons programs; on the contrary, they have accelerated their programs since the invasion of Iraq as a means of deterring a U.S. attack.

Our experience in Iraq has discredited the U.S. intelligence community and the neoconservatives’ fantasy assumptions about OIF’s strategic and political consequences. It has also underscored the perils of relying on preventive war as a substitute for traditional deterrence.

Prewar administration statements dismissed the reliability of deterrence against fanatical terrorist organizations and rogue states, failing to distinguish critical differences between the two in character, aims, and vulnerability to U. S. military power. Administration spokesmen argued that Saddam Hussein, once in possession of nuclear weapons, would be undeterrable, that he would feel emboldened to run amok in the Persian Gulf and even attack the United States itself. The only way to eliminate this threat was to eliminate the regime itself, before it could acquire nuclear weapons. Because rogue states “see WMD not as means of last resort, but rather as weapons of choice…[as] tools of intimidation and military aggression,” announced President Bush in his 2002 “axis of evil” speech, “the United States will, if necessary, act preemptively.”

OIF can thus be viewed as the first war aimed at stopping the proliferation of nuclear weapons. Unlike deterrence, which focuses on thwarting the use of nuclear weapons, OIF sought to deny their acquisition. We know now, of course, that Saddam in 2003 had no nuclear weapons program worth the name.

But in 2003 we also knew that neither Saddam Hussein’s Iraq nor any other rogue state had ever employed weapons of mass destruction against enemies capable of inflicting unacceptable retaliatory damage. Though Saddam had used chemical weapons against helpless Kurdish villages and Iranian infantry in the 1980s, he did not use them against U.S. or Israeli targets in the Gulf War of 1991.

More to the point, even had Saddam Hussein managed to build a few atomic bombs, he would have been no more able to escape the reality of credible nuclear deterrence than the Soviet Union before him or North Korea today. As Condoleeza Rice declared in 2000, against rogue states, “the first line of defense should be a clear and classical statement of deterrence-if they do acquire WMD, their weapons will be unusable because any attempt to use them will bring national obliteration.”

The administration rightly questions the utility of deterrence against fanatical terrorist organizations like al-Qaeda. But rogue states, unlike terrorist organizations, have assets–territory, population centers, economic infrastructure and governments-that can be held hostage to devastating U.S. retaliation. Saddam Hussein always loved himself more than he hated the United States. And in 1991, when he had vast stocks of chemical weapons, he was deterred from using them against the Coalition and Israel by credible threats of obliteration..

The administration’s lumping together of al-Qaeda and Saddam Hussein’s Iraq as a common terrorist enemy was a strategic error of the first order because it ignored the effectiveness of deterrence against Iraq, and in so doing, encouraged an unnecessary preventive war based, as we now know, on a massive intelligence failure and a host of faulty assumptions about our ability to create stability and democracy in post-Saddam Iraq.

In the final analysis, it is not rogue state possession of nuclear weapons that threatens the United States, but rather the prospect of their use. Accordingly, in dealing with the likes of Iran, North Korea, and other hostile nuclear wannabe states, the United States should return to its traditional-and successful-strategy of deterring their use. The alternative of preventive war to stop their acquisition simply invites repetition of what we have encountered in Iraq: diplomatic isolation, military dissipation, and an expanded terrorist threat. Creating and maintaining credible deterrence is not easy, but it’s a far less unattractive choice than starting unnecessary wars.