Over eight years of inspections, Saddam's deceptions and the increasingly restrictive rules of engagements U.N. inspectors were forced to negotiate with the regime undermined efforts to disarm him.

To conclude before the war that Saddam had destroyed his existing weapons, we would have had to ignore what the United Nations and allied intelligence said they could not verify.

The third stream of information came after the U.N. inspectors left Iraq in 1998. We gathered intelligence through human agents, satellite photos and communications intercepts. Other foreign intelligence services were clearly focused on Iraq and assisted in the effort.

In intercepts of conversations and other transactions, we heard Iraqis seeking to hide prohibited items, worrying about their cover stories and trying to procure items Iraq was not permitted to have.

Satellite photos showed a pattern of activity designed to conceal movement of material from places where chemical weapons had been stored in the past. We also saw reconstruction of dual-purpose facilities previously used to make biological weapons or chemical precursors.

And human sources told us of efforts to acquire and hide materials used in the production of such weapons.

And to come to conclusions before the war other than those we reached, we would have had to ignore all the intelligence gathered from multiple sources after 1998.

Did these strands of information weave into a perfect picture? Could they answer every question? No, far from it. But taken together, this information provided a solid basis on which to estimate whether Iraq did or did not have weapons of mass destruction and the means to deliver them.

It is important to underline the word "estimate," because not everything we analyze can be known to a standard of absolute proof.

Now, what exactly was in the October estimate? Why did we say it and what does the postwar evidence thus far show?

But before we start, let me be direct about an important fact. As we meet here today, the Iraq Survey Group is continuing its important search for people and data. And despite some public statements, we are nowhere near 85 percent finished. The men and women who work in that dangerous environment are adamant about that fact.

Any call that I make today is necessarily provisional. Why? Because we need more time and we need more data.

So what did our estimates say? Let's start with missile and other delivery systems for weapons of mass destruction.