I COULDN'T HAVE SAID IT BETTER MYSELF: In an apparent attempt to come out against war with Iraq without actually saying so, the NY Times' editors praise the doctrine of deterrence:
...Some of the debates that preceded its adoption sound strikingly similar to arguments being made today. During the Truman administration, some strategists suggested attacking the Soviet Union while it was still militarily weak to prevent the rise of a nuclear-armed Communist superpower. Wiser heads prevailed, and for the next 40 years America's reliance on a strategy of deterrence preserved an uneasy but durable peace.
One advantage of deterrence is that it induces responsible behavior by enemies as a matter of their own self-interest. Even dictators tend to put certain basic interests above all else — pre-eminently their survival in power, with their national territories and a functioning economy intact. Aggression becomes unattractive if the price is devastation at home and possible removal from power. By contrast, the threat that America will strike first may give foes an incentive to use their military forces, including unconventional weapons, before they lose them.
The logic of deterrence transcends any particular era or enemy. It has worked, for example, to restrain further North Korean aggression since the Korean War. A decade ago, a clear message of deterrence delivered by the first Bush administration persuaded Saddam Hussein not to use his chemical and biological weapons against America or Israel during the Persian Gulf war.
...[B]y and large, we believe that deterrence can still be a powerful force in managing many of the threats the United States faces. Protecting America's security requires weighing all available policy options and choosing the wisest. Deterrence, the least risky and most time-tested tool in America's national security arsenal, should not be hastily discarded.

I agree. And that is why Saddam Hussein must not be permitted to gain weapons that would enable him to deter us from checking his aggression, even if that means war.
As an aside, the debate over Saddam has eerie similarities to the debate over missile defense, in the refusal of most people on both sides to acknowledge that a main issue was not our ability to deter others, but others' ability to deter us. See this Lawrence Kaplan piece and this Robert Kagan article. Also see this skeptical Bill Keller article.