AUSTIN, Texas -- I'm not a weapons expert, and you're not a weapons expert, so how are we supposed to know whether the National Missile Defense system is a good idea?

Even if you've read enough about it to be skeptical, there are real, actual experts claiming that it's a dandy notion. Generals at the Pentagon bent over double with brass want this thing. And many, many of the politicians of our nation agree that it will be a bonanza of contracts for defense plants in every congressional district.

So there it stands (well, actually, it doesn't -- it keeps blowing up): a monument to our nation's peculiar political and weapons procurement systems.

You may recall that the last time they tested it, the booster thing attached to the kill-thing that's supposed to fly off and hit the incoming missile failed to come apart from its other thingie, and went gerblob instead. (See? Anyone can discuss National Missile Defense.) That cost us $100 million.

And the time before that, it turned out that the Pentagon had cheated to make the missile-hitting missile look good.

First, we had a whistle-blowing senior engineer at TRW who said that the company has faked tests and evaluations of its component of the missile defense system. Then the Pentagon's director of operational test and evaluation said the tests were "highly scripted" and "not as challenging" as the conditions that would actually be needed to knock a missile out of the sky.

Now, I don't know what you think of a weapons system where they have to rig the tests to make it look good, but if we're building this $60 billion toy to foil Saddam Hussein, I don't think he's going to give us any advance clues on which is the decoy and which is the McCoy. It turns out that our National Missile Defense system can't tell an incoming missile from a mylar balloon.

As we all know, this thing started as Ronald Reagan's "Star Wars," aka the Strategic Defense Initiative. When SDI kept getting bad publicity, they changed it to National Missile Defense, so now it's called NMD.

Reagan was a great optimist but not much of a detail man. I regret to report that those who have researched this topic believe that Reagan got the idea for Star Wars from a movie called "Torn Curtain" starring Paul Newman, who should be ashamed of himself. (This just goes to prove Sen. Joe Lieberman's point that those Hollywood people should show greater responsibility because you just never know whom they're going to influence.)

The actual building of what is essentially a bullet trying to hit a bullet with a closing speed of 10,000 mph presents a few engineering challenges and has the classic defensive-weapon problem.

I am informed by a source at Los Alamos that, as a rule of thumb, a defensive weapon costs at least seven times as much as an offensive weapon. That's why, in the history of warfare, it has always proved cheaper to build a lot of offensive weapons and thus overwhelm the defensive ones.

In the case of NMD, our enemies don't even need to build real offensive weapons; all they have to do is build a lot of decoys and see if the NMD can figure out which is which.

But, not being weapons experts, we can set aside the engineering problems with great cheer; and being veteran American taxpayers, we can set aside the $60 billion (not counting those ever-lovin' cost overruns, already mounting) price tag on this baby, because if we aren't used to the Pentagon wasting our money by now, we never will be.

However, there's another element to this.

According to a report on a new national intelligence estimate ("Foreign Responses to U.S. National Missile Defense Deployment"), building a missile defense system will cause China to "significantly accelerate its production of nuclear weapons beyond current plans, according to officials familiar with the document." The estimate is classified, but it was on the front page of The New York Times last week because this is a great nation and that's how we do these things.

Not to diss the whizzes behind the national intelligence estimate, but ... duh. This is precisely what China and Russia have been telling us and telling us and telling us.

You see, to them this does not look like a defensive weapon to protect us from nations formerly known as "rogue" and now known as "of concern." This looks to them like a clear case of us trying to get the capability for a first strike with no possibility of return damage, thus wiping out their nuclear deterrents, thus destabilizing the whole mess once again and setting off a fresh arms race.

The world does not need more nukes. You do not have to be an expert to understand this. The pols are too dumb to stop this (the Senate wouldn't even vote for more stringent and thorough testing), so it's up to us. Report for duty at your nearest arms control group.

Molly Ivins is a columnist for the Fort Worth Star-Telegram. To find out more about Molly Ivins and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate web page at www.creators.com.