The most incredible revelation in the new CIA report on Iraq’s weapons of mass destruction is not that there were no biological, chemical or nuclear weapons in Iraq. We knew that.

It is that Saddam Hussein deliberately deceived the world — even members of his own regime — into believing he still had WMD in order to deter Iran.

Saddam emerged from the nearly decadelong war with Iran in the 1980s believing that only the use of chemical weapons and ballistic missiles had staved off an Iranian conquest. His decision to accelerate the Iraqi nuclear program in the late 1980s was driven by concerns about Iran’s nuclear program. As his intelligence service came back with reports on Iran’s progress toward the bomb in the 1990s, Saddam concluded he had to create the deception that Iraq still had WMD to hold off the Iranian threat.

Those insights come from extensive interviews with Saddam and his captured inner circle, along with documents and tape recordings of their deliberations. The detailed account of the regime’s “Strategic Intent” that opens the huge report issued last week by Charles Duelfer is in sharp contrast with the cartoon images drawn for the American people.

For Iraq, Israel was “a more distant second as their primary adversaries,” the CIA said. “Saddam did not consider the United States a natural adversary, as he did Iran and Israel, and he hoped that Iraq might again enjoy improved relations with the United States,” the report found. In fact, Saddam made repeated overtures during the 1990s, including through Duelfer personally, to improve ties with the United States.

Saddam was also wedded to a belief in the utility of WMD. They not only saved the war with Iran, but also stopped the United States from driving to Baghdad at the close of the Persian Gulf War in 1991, he thought. Possession of WMD would give Iraq prestige and strategic influence throughout the Arab world, Saddam believed.

The nuclear and chemical weapons, along with the missiles, were destroyed in 1991 under the supervision of United Nations inspectors. Saddam tried to hide his bioweapons, but after the defection in 1995 of his son-in-law, who had run the WMD programs, that too was destroyed.

Increasingly Saddam was desperate to lift the effective international sanctions that brought Iraq’s economy to ruin.

“This led to a difficult balancing act between the need to disarm to achieve sanctions relief while at the same time retaining a strategic deterrent,” the CIA report said. “The regime never resolved the contradiction inherent in this approach.”

Saddam tried to resolve the dilemma by creating the impression that he might still have WMD somewhere in hand. Because of the secretive nature of the regime, even Saddam’s own military officers and senior officials were uncertain about whether there still might be WMD.

This deception was a fatal mistake, compounded by Saddam’s miscalculation, up until the end, that the United States would not launch a full-scale military invasion of Iraq. When Bush labeled Iraq a part of the “axis of evil” in January,2002, Saddam told his aides: “What can they discover, when we have nothing?”

During this time, the CIA documents show, Saddam had become increasingly isolated within his own regime. Fearful of assassination by the CIA, he had very little contact with anyone but close family. He tried to block U.N. inspections of his palaces because he thought it would allow the United States to pinpoint his exact location. His military commanders lied about the state of their forces.

Saddam bears the chief responsibility for his grandiose ambitions and the consequences of his tragic bluff.

It is also evident that the Bush administration, and the Clinton administration before it, had a dangerous lack of understanding of their foe.

Read this report and think of North Korea, whose leader is also portrayed as a caricature but who also clearly shares Saddam’s belief that WMD, or the claim to have them, are needed to deter a real threat.

And think too of the radical Islamic regime in Iran, moving steadily as Saddam feared toward nuclear status, now emboldened by the American removal of their foe.

— Daniel Sneider is foreign affairs columnist for the San Jose Mercury News.