One of the complaints I've often heard is: "The U.S. says they have intelligence indicating where Iraq is hiding some WMD or WMD capabilities. Why aren't they telling the public or weapons inspectors?"

There are several perfectly sane reasons for this...

To explain, start by recalling that the goal is a disarmed Iraq.

First, let's consider voluntary disarmament where we expect Saddam, of his own will, to disclose the places where he's keeping WMD technology. If and when Saddam comes forth with a declaration, how will we know if he's telling the truth? How could we be confident he'd told us the whole story?

Let's consider some facts about our secret Iraqi WMD intelligence: We probably only know a few facts about Iraqi WMD, a few locations where things are being stored. But we don't know how much is out there of which we are unaware. Its possible, likely even, that we only understand a very small part of Iraq's WMD picture. (And even if we actually did know the whole thing, there'd be no way we could realize that now.)

Let's imagine he decides to 'co-operate', and reveal, say, ten locations containing WMD to us. How can we be confident he's come clean? How can we know there aren't 200 more locations out there where WMD is hidden?

The only way we can be sure is if we already know about some of that WMD, and we don't tell anyone. Then, when Saddam 'fesses us', we can examine his declaration: If all the stuff we've kept secret is in the list, we might start to think he's playing fair. If, on the other hand, we see things missing from the declaration then we know the declaration is still only the tip of an iceberg.

[In fact, we can guess the size of the hidden iceberg by how much he's disclosed. If we know of ten hidden things, and we see a list of twenty things, and only two of those ten things on the list, we can guess that we're seeing one-fifth the picture; that about 80 more things are still hidden somewhere.]

If we were to tell the public everything we knew first, then Saddam would only declare the things he knew we knew.

Remember "Wild, Wild West"? When Jim West put the gun from his holster on the table, we knew he probably still had another one hidden in his shoe. And a garrot in his belt. And a throwing knife up his coat sleeve... You never knew when the boy was out of weapons. But if we already knew some of his tricks, we might be able to tell when he was being earnest about disarming. Same with Saddam.

So why not tell only the weapons inspectors? One problem is that we're not sure we trust them not to leak the information to Iraq (as the French inspector did last time around), thus allowing Saddam to move the WMD and keep it. And making us look stupid.

And even if the inspectors did keep secrets, it misses the point. The goal is to remove the entire iceberg, not just the tip -- the portion of which we're aware.

Further, each time we let a secret go, its one less way we have of verifying disarmament in the future. And remember, we probably don't have very many secrets to share.

Even more damning, when we release secret intelligence, and Saddam finds out what we know (either by a leak, or just when the weapons inspectors go to that location), he also is able to figure out how we knew it. Remember: probably no-one in Iraq but Saddam & son understands the whole WMD picture. As under his hero Stalin, information is highly compartmentalized -- each trusted individual only knows a small piece of the picture. When a leaked fact is known, Saddam is going to only have a small number of possible suspects. And knowing Saddam, just to be safe, he'll torture and kill each of them. And their extended families. And that will be a double tragedy: Lives will be lost, and so will vital future intelligence.

Finally, if we are unable to get a voluntary disclosure and disarmament, this information will be necessary when attempting to disarm Saddam by force.

Again, I'm not trying to argue if or when we should deploy the military. I'm just pointing out why U.S. intelligence isn't laying all its Iraqi WMD intelligence cards on the table. And why that makes complete sense.