The CIA’s newly declassified judgments on the likelihood of Iraq’s use of weapons of mass destruction severely undercut the Bush administration’s case for attacking Iraq. The CIA noted that Iraq now appears to be deterred from initiating terrorist attacks against the United States with conventional, biological or chemical weapons. But if the United States invades Iraq and attempts to depose Hussein, the CIA concluded that he would be more likely to conduct such attacks. In fact, according to the CIA’s analysis, Hussein might decide that the extreme action of helping radical Islamist terrorists in carrying out a biological or chemical attack on the United States would be his last chance to get revenge by taking a large number of American victims with him. The CIA’s now declassified assessment confirms what opponents of a U.S. invasion of Iraq have been arguing in public all along.

The uncovering of such analysis shows that the policy of deterring and containing of Iraq does work and that a more aggressive policy of invasion could prove disastrous. The U.S. government’s national security policy is supposed to enhance the security of the nation, not reduce it. Risking terrorist attacks against the United States with conventional, biological or chemical weapons merely to remove a thug who has been successfully deterred and contained for more than a decade defies common sense.

Deterring and containing Iraq should be a much more manageable task than the successful deterrence and containment during the Cold War of a rival superpower—the Soviet Union—which possessed thousands of nuclear warheads and an ideology of worldwide communist expansion. Despite hostility between the superpowers, the United States did not launch an attack against the Soviet Union to prevent it from becoming a nuclear power. Neither did the United States attack a radical communist China under Mao Zedong as it obtained nuclear weapons during the 1960s.

Rather than rotely insisting that opponents of attacking Iraq must prove that the diabolical tyrant Saddam Hussein would not launch an unprovoked attack on the United States with weapons of mass destruction, the president could better spend his time looking at the historical record and examining Hussein’s incentive structure (as the CIA apparently has). In fact, because the president is the one who will put American sons and daughters in harm’s way, the burden of proof is on him to show that it is not possible to continue deterring and containing Hussein.

Saddam was deterred during the Gulf War and ever since from attacking either the nuclear-armed United States or Israel with biological or chemical weapons. That’s because, at the time, the United States threatened to use nuclear weapons in response to any Iraqi use of biological or chemical agents. Saddam previously used biological and chemical weapons against the Kurds and the Iranians, but these opponents do not have huge nuclear arsenals that could be used for massive retaliation. Even in the worst case—if Iraq got nuclear weapons—the thousands of nuclear warheads in the U.S. arsenal should deter Hussein, who would only possess a few.

Hussein has also refrained from giving or selling biological and chemical weapons to the Iranian and Palestinian terrorist groups that he supports. Radical terrorist groups—including al Qaeda—in possession of such weapons and without a home address, could get the Iraqi government, which has a known location and a leader whose primary goal is survival, into a lot of trouble with the great powers. Saddam, ever paranoid, does not even let his own regular military units have biological and chemical weapons, so it is unlikely that he would give them to terrorists.

In its analysis, the CIA has apparently discovered such disincentives for Iraqi use or transfer of superweapons. But the CIA also understands that if the United States invades Iraq, Hussein’s incentives change dramatically for the worse. Saddam could become a loose cannon and do exactly what the Bush administration is trying to prevent with an invasion. Under the deterrence and containment strategy, Saddam is like a lion in a cage. The threat that he poses has been circumscribed. But the Bush administration’s apparent desire for an invasion is like going into the cage with a stick and trying to kill the lion. The United States has a big stick and can probably kill the lion, but must expect to be bloodied in the process. Getting bloodied when the threat was already contained does not seem sensible.

But will the CIA’s astounding assessment put a damper on the invasion plans? In Washington, the invasion train has already left the station and is steaming down the track. Some of the more alert passengers are telling the engineer that a truck is blocking the tracks up ahead, but the engineer insists on opening the throttle wider. Unless the unlikely occurs and the train is stopped, a bloody mess could ensue.