No matter... it's certainly been one of the livelier threads around here in the last month or so.

I wish I had the patience to sit and listen through a whole show to get information off NPR. I miss good stuff that way. They charge for transcripts.

The link in my prev' post was to the story itself, not the whole show (FYI, I do that whenever possible). It should still take you there.

Is the assumption that somehow we will be able to attack the launch sites before the missiles can be launched? Hope our enemy doesn't have missile subs. Or that the missile will come from the nation that we expect to attack us.

The assumptions about enemy capability and just who "the enemy" is are central to the whole argument. I will go so far as to say the meta-argument -- that is, what you term the political argument, which is not only necessary but vital in a democratic republic with civilian oversight of the military -- is whether or not there is an enemy at all.

Let me put it another way: Why, in the 21st Century, is it still necessary to assume that any other nation-state will attack the US? I thought St. Ron ended the Cold War, and with it the concept of one country nuking another over simple, howsover profound, ideological differences.

Getting back to the comment made in the NPR story: the subject therein was specifically North Korea, and the answer to your question in that case is, "Yes the assumption is that ICBM launch sites are too big to hide, and can be sufficiently disabled before the weapons are delivered to them."

That leads to consideration of other "enemies", who either already have nukes and the missles to deliver them (as in your submarine scenario), or who may develop both components and think about using them. My first response (pun not intended, but I'll take anything I can get) is: "Isn't MAD still the operating doctrine?" Isn't retaliation still a sufficient deterrent? It's worked for 50 years (or thereabouts) with all of the countries who are capabale of nuking us. In spite of dozens of scenarios (played out sometimes in fiction) involving a rogue madman with his finger on The Button, no one, either person or country, has yet been quite that insane.

So what are we defending ourselves against?

Since 1941, the only successful attacks against Americans not actually engaged in battle at the time have been carried out by guerillas using conventional explosives delivered by standard ground transporation vehicles -- with the exception of four passenger airliners and the Zodiac that blew a hole in the Cole. That includes the embassy bombing in Kenya, the Marines in Lebanon, and the incidents in Saudi Arabia and Oklahoma City. In no case was a nation-state directly involved, nor a missile, nor a warhead that required massive R&D, and processing plants, to construct.

What exactly is the necessity of a missile defense?

If a single city is saved in the entire operating life of the system, it will have paid for itself ten times over.

Well, yes -- there's no arguing from fact against a speculation like that. 'Having it and not needing it' is always better than 'needing it and not having it'. Fire protection systems are installed in buildings with the same philosophy. All of us "of a certain age" remember the Nike anti-aircraft installations (they'd be called SAMs now) built in response to a perceived threat of Soviet bombers. Nevertheless, in the case of ballisitc missile defense I continue to question the dollars spent as compared to the genuine risk.

I'm not saying that the system is problem-free, but it needs to be worked on and developed.

Would that it were that simple . . . However, current policy is committed to deploy while still in test phase. It sounds to me like the Pentagon is taking product development lessons from Microsoft.

I've been following this since Reagan . . .

A cynic might reply: that indicates a 20-year-old approach to problems raised in 40-year-old war scenarios.

. . . and a lot of the opponents are operating from the premise that even workable missile defense is a bad idea.

Aye, there's the rub: "workable".

The other option is preventing, by hook or by crook, enemy nations from developing missiles at all.

It's not the missiles per se, but what's on their business end. Nuclear non-proliferation, and prevention of theft and clandestine purchases, is much more important.

God knows Israel needs missile defense very badly.

And I believe they're developing their own, to match their actual needs: short-range ballistic missles launched at them with far less warning time.