If there is a poionous snake in your backyard do you wait until it bites and kills a member of your family or do you take a shovel, dig it out of its hole, and cut its head off?
The point of taking Saddam out was not that we were certain he possessed chemical, biological, or nuclear weapons. The point was that he did in the past and had the infrastructure in place to make them again. The latter fact was what Colin Powell established in his speech to the UN and it is now documented in the October 2 report.
Our worry here, tragically based on recent experience which of all people I'd expect a Russian to understand, is that the next attack on us won't involve the killing of a few thousand but a few million. Now, something like may very well happen anyway, but we will do our best to reduce the odds.
The war to depose Saddam was preventative and as a side or perhaps even prime benefit it allows us to take our troops off Saudi Arabian soil and thereby remove one major recruiting tool of the radical Islamists.
You are entitled to your opinion, but one of the last words I'd use to describe the elimination of a regime like Saddam and his Baath Party is "mistake".