So it was important, I felt, that people understand the limitations of these early tests in the context of a deployment decision. That was what was different.
You were worried ... [that] some people in the Congress and the Pentagon didn't understand what was going on with the tests?
Yes. These are very complex tests. They cost close to $100 million apiece. There's all kinds of equipment, some specifically just for the purpose of the test ... [and] all of these complexities are hard for people to keep up with and understand. I was concerned about that. ...
Was there also a feeling, both within the program and within the Pentagon, that there was political pressure to make this happen, and make it happen quickly?
I think then, and today, there are people both in the Pentagon and in the Congress who would like to see a national missile defense system successfully developed, built, and fielded. If we knew how to do it, especially if we knew how to do it at some reasonable cost, I think most Americans would feel the same way.
So then, as now, yes, there was pressure to move this program forward as fast as possible.
Tell me about that day ... on Kwajalein. You're in a control room of some sort?
Yes. For these tests, everybody goes into a sort of underground bunker for some protection. The interceptor rocket has a lot of propellant in it, and it could conceivably have an accident, blow up or something. So everybody is in a protective shelter. You basically watch the test, the final parts of the test, on closed-circuit television. ...
Before the test actually occurred, it turned out that Greenpeace had sent some protestors over to the island in a Zodiac boat. So one of the first things we saw on closed-circuit television was the two people from Greenpeace walking up the beach toward the interceptor. ... The Army had to convince them that they had had their intended effect -- they had delayed the test, which is what they wanted to do -- and get them off to safety.
But then, later, the target rocket was fired from Vandenberg. Then you wait for it to get closer to Kwajalein, and the finally the interceptor is launched. It's just like you would expect on television. You see all the smoke and fire from the first stage of the rocket. ...
So how long was it after launch of the interceptor that the people in the control room knew that this had failed? How did it fail?
We knew within I think 15 minutes or so that it had failed. The reason ... was because the interceptor rocket didn't perform properly and as a result, the interceptor never got close enough to the target to hit it, hit to kill. It went way awry, and there was no chance that it was going to hit the target.
So what was the reaction in the control room?
Oh, everybody was very down, very blue. These people have put an enormous amount of effort in every one of these tests. A huge amount of effort goes into these tests. People are up nights and weekends and working long hours, and if they're at Kwajalein, they're away from their homes and families maybe for months on end.
So a huge effort has gone into tests like this, and everybody was very disappointed. ... It was just totally silent. I can't remember how long it was, but for a long time, nothing was said. You saw the same thing in Washington where in the control center in Washington, General Kadish and others were watching the test from there. ...
When they first realized that the interceptor had missed, nobody could say anything. Everybody was stunned. ...
[Later, you] issued a report. What did that report say?
It was about a month later. The report that I and my staff wrote described all of the tests that had taken place so far, including the most recent two, both of which had failed. [We] described what was realistic and what was not realistic about those tests, all of the tests; described all of the things that the program still had to do, which were many; and basically concluded that, in our view, the program was not ready for deployment, and wouldn't be for many, many years.
Were you critical of the structure of the tests?
We found fault with some aspects of the tests. For example, the intercepts are conducted fairly close to Kwajalein. ... In a real battle, a real war, you wouldn't wait until the enemy missile nearly had reached the United States. If you could, you'd reach out and get them way out in the distance.
So we felt that eventually there needed to be tests where intercepts were conducted at much greater ranges from Kwajalein than anything that had been attempted at that point or since. We also felt that there were other artificialities in the test, artificialities which were perfectly understandable for such early developmental tests as these were, but which were not acceptable if you were thinking about deployment. ...
Critics have charged that these tests have been fudged in some way. Is that true?
... I don't think anybody has ever cheated. But there are artificialities in these tests, and critics have pointed out that they certainly look like cheating. For example, the target, the surrogate enemy target, the re-entry vehicle has a sort of a beeper on it, a beacon, that tells you where it is. It also has a global positioning system on it. Obviously an enemy wouldn't tell you with a beeper, "Here I am."
In an early test, there's nothing wrong with something like that. It's a surrogate for a forward-based early warning radar that we didn't have in the tests at that point, and probably won't for many years. So for an early test, it was not a bad thing to have. But to a critic, it looks very artificial, and it's something that I know the program will seek to eliminate as the years go by. ...
Describe for me the difference between developmental and operational tests.
Developmental tests focus on ... achieving certain detailed technical specifications such as speed or maneuverability or something like that. Operational tests are tests that are very real world. In operational tests, the equipment is operated by soldiers or sailors or airmen or Marines, not by contractors, as they might be in a developmental test. The tests may have to be conducted at all times of the day and night, in bad weather, in dust and dirt and mud and rain and snow and all of the things that can happen in battle, the kinds of things we see on television today from Afghanistan. ...
So in an early developmental test, for example, you might have prior information about when the target's going to be launched, what the trajectory is, what the re-entry vehicle looks like that you're going after with your interceptor. You might have prior information about all those things that you might never have in a real battle.
[Editor's note: For more information about operational vs. developmental testing, see "The Basics: Making Sense of Missile Defense."]
... Essentially, as I understand from what you've said, for this system ever to have a hope of working, you have to have prior information?
Yes. You need to know when the enemy missile is launched. You might see that with one of our satellites and if you do, you'll know that. But if you miss it with the satellite, you might not know when it was launched.
You need to determine what the trajectory is. Again, you might determine that with satellites or with ground-based radar systems, but again, if you've missed some of that, you're missing important information.
Finally, when it comes time for intercept, you need to know what the re-entry vehicle looks like so that you can teach the computer, the brain on the interceptor and its sensors, infrared seekers, what to look for. ...
This is hard for humans to think about. With our brains and with our eyes, we look at these things and we see this decoy and we see this real re-entry vehicle, and to us, it's obvious which is which. But to a computer and a pair of infrared eyes, it's not obvious at all. ... These objects just look like little points of light, just sparkling points of light. They don't look like a real object, especially not to the sensor and the computer.
... So how do we get the prior information?
Obviously our intelligence community would work very hard at that. Our military would work very hard to try to learn as much as possible about enemy missiles. They do that all the time. ... But an enemy who understands that we can be fooled if they keep these things secret -- if they don't test the exact same thing so we don't learn from their flight tests how they did it, if things like the re-entry vehicle are shrouded, covered up in the missile anyway so we never do see them -- they could easily launch a missile toward us, parts of which we'd never seen before.
... The intelligence prowess is more important that technical prowess in this situation?
Exactly. Some people say, "Well, I have more faith in U.S. technology than in, say, the technology of North Korea." I think we'd all agree about that. But that's really not the issue. The issue is, will we have the right intelligence about what the enemy missiles look like, what their re-entry vehicles look like? Will we know all of that and will we know it enough in advance to do something about it?
If we're surprised like we were on Sept. 11, if we're surprised as we were in the USS Cole incident, that would not be a good thing if the analogous thing would happen with an enemy missile attack.
If our intelligence is working that well, wouldn't we have other opportunities to solve the problem?
Yes. If we have information that, say, North Korea is building a missile to be launched at the United States or somebody else, for that matter, if we have that kind of information about when they're going to launch it or what it might look like, we would go blow it up on the ground. We wouldn't wait until it had nearly gotten to Los Angeles to try to shoot it down. ...
If we have the intelligence necessary, then why do we ever get to the point of needing a national missile defense as is being discussed today?
That's the biggest challenge for national missile defense, namely, can the United States build a national missile defense system that's more effective, more reliable, more sure than the attack operations that we've seen in Afghanistan? It's a very high bar for missile defense to achieve.
What is your ... answer to that?
I think we'll be able to do it for short-range missiles overseas, missiles that aren't attacking the United States but which are trying to attack our troops in the Middle East, perhaps, or on the Korean Peninsula or wherever they might be deployed. ...
The PAC-3 system -- ... the Patriot Advance Capability III -- has come along quite well. It still has a long way to go, and hasn't yet been tested against threat representative targets of the kind that it will have to deal with. But I think we'll learn how to do it for short-range missiles.
It's much more difficult for long range missiles, ICBMs, and [is] going to take many, many years. Some things that the program is trying to do are essentially impossible.
One of the things that's very difficult to do is to protect the United States in the so-called terminal phase, when the enemy missile has made it all the way across the oceans and is now re-entering the atmosphere over the United States. That's a very difficult job.
The advantage of trying to shoot down a missile in the terminal phase is that you use the atmosphere to strip out the decoys. In effect, they sort of float away from the re-entry vehicle and so you don't have to worry about the decoys. But you've only got maybe 30 seconds ... during which you can take advantage of that effect ... and the defended area of terminal interceptors is very small. So you would need hundreds of them all across the United States. ...
Some people think that the missile defenses we are building will work against a large country like China or Russia in the boost phase -- that when the enemy missile is still ascending, still boosting up into outer space, we can shoot it down during that period.
The advantage of shooting it down during that period is that you blow up the whole missile, decoys and everything. So you don't have to worry about the decoys later on, as you would in the midcourse. However, to do that, to shoot down an enemy missile in the boost phase, you've got to get close and you've got to be very fast. You don't want to be in a tail chase, because you probably can't catch up. So it takes very fast missiles, and you have to be close.
Well, for a country the size of China, the country is simply too big. You just can't get close enough without invading China first. ... Same would be true for a country like Russia. So there are people in Congress and people, I believe, in the administration, who think that the money they're spending, among other things, will produce a missile defense against Russia or China in the boost phase. And it won't. ...
The same is true for countries that are not quite as big as China or Russia. For example, Iraq is a pretty large country. So is Iran. And there are geopolitical problems in placing interceptors close to those countries, anyway. ...
Let's talk about midcourse and the problems of the decoys. What is the description of midcourse?
The midcourse of an intercontinental ballistic missile is the period of flight after the missiles have gotten outside the atmosphere on the way up and they haven't yet gone back into the atmosphere on the way down. It lasts maybe 20, 30 minutes. It's the time when the enemy missile, all the debris that came along with it -- from the rocket stages pushing it up there and any decoys or countermeasures that they might have put in there also, chaff, things like that -- ... is spreading out and is floating along together.
Out in space, a feather moves just as fast as a lead brick, and it's hard for us to think about that but it does. So you can have a balloon that looks just like a re-entry vehicle floating along with a re-entry vehicle which is much heavier, much more dense, will have different aerodynamic properties when it finally gets close to the United States. But out in space, it's very hard to tell them apart.
What kind of problem does that create?
The problem with decoys and countermeasures is that your sensors, radar sensors on the ground and the infrared sensors on the interceptors, have to be able to tell these objects apart. They have to be able to tell the warhead ... from all the other debris, things that are blinking and moving around, and which may look very similar to that re-entry vehicle.
I talked to someone yesterday, a non-scientist, who said there was no law of physics of which he was aware that would prevent the U.S. from solving this problem of discriminating against decoys.
Well, the way these infrared sensors work is they are picking out a cold object, namely, the enemy's re-entry vehicle. Out in space, it's very cold. ... The background of space is also very cold. So one scheme that is very challenging ... [is if a decoy] is basically refrigerated and shrouded, so that it looks to be the same temperature as the real re-entry vehicle.
Now indeed this would be difficult to build. But anybody who's smart enough to build an ICBM with all the guidance systems and everything else could probably do that also. ...
So what do you say to people who essentially say, American science and ingenuity has always accomplished what it wants to accomplish? ...
Technology has been the showstopper for national missile defense for all of the 30 or 40 years that it's been on the American political scene. The particular technology that we've tried to use at each phase has changed over the years, but it's always been very difficult. ...
I think we'll be able to learn how to shoot down short-range missiles like Scuds overseas in places like the Persian Gulf. It's much more difficult when the missiles are long-range missiles and when they are launched with these huge rockets that can also send up decoys and countermeasures and chaff and everything else along with the real target. Much more difficult then.
You've written that the technology lags the political fervor ... for national missile defense.
All of the various pieces of missile defense have suffered ... cost overruns and large delays. Just since I left the Pentagon, programs that were supposed to have done something by now have slipped ... two or three years. I fully expect it will slip two or three years more. The technology is very difficult and while the administration is giving the program every priority, it's just very difficult.
[Some have said] that the system must work flawlessly. In some ways ... more so than other military systems. Can you explain that to me?
... Secretary of Defense Bill Perry has pointed out that if you go back and look at ... air defense systems -- the kinds of systems that we have today and used in World War II to shoot down enemy aircraft -- that you're doing good if they work, say, 25 percent of the time.
You don't [destroy] 100 percent of the attacking aircraft. [It's] a situation where you have a war of attrition. You shoot down 25 percent in the first wave and you shoot down 25 percent in the second wave and eventually you get most of them. But it takes days and weeks to do that, maybe longer. If you're talking about a missile attack, you only have one chance.
Now that's why the Bush administration is emphasizing a layered system -- boost phase, midcourse, terminal. But there are serious difficulties with each of these phases. So even with a layered system, it will be very difficult to get high reliability, high performance.
Secretary Rumsfeld has cancelled the requirements that were on the books for these systems. Now they are pursuing the development on a capability basis, namely, trying to do the best they can, because the requirements that had been set before were simply too difficult.
... Cancelled the requirements?
Yes. In the decision memorandum where he authorized the creation of the new missile defense agency and changed its name from the Ballistic Missile Defense Agency to the Missile Defense Agency ... he cancelled the requirements that had been on the books that these various missile systems would have to meet.
They are very stressing requirements. The way the program is going to go forward is they're going to simply do the best they can. In some areas, it may be fairly good, like with PAC-3. In others, it may not be very good at all.
But without requirements to measure against, how do you know what you're doing, what's succeeding?
At some point, as they hope to deploy these systems, they're going to have to say, "Hey, these are the 'no-kidding' requirements this system has got to meet." At that point, the tests that will be conducted will be operational tests, and will be conducted against those requirements. But for the foreseeable future, there are no requirements on the books for these systems now. ...
How do you answer the criticism that ... the reason that we're no further along with a system of national missile defense than we are is because of the ABM Treaty?
The ground-based, midcourse system that covers the middle part of the trajectory of an enemy ICBM can be developed, was being developed, and is being developed within the constraints of the ABM Treaty. President Clinton didn't want to violate the ABM Treaty any more than President Bush does. So all of the work that you've seen about in the news, these tests from Kwajalein and Vandenberg and all of those tests can and are being conducted within the constraints of the ABM Treaty. So that piece of the Bush layered system isn't a problem.
Well, what about boost-phase defenses? They have to be mobile, either on a ship or perhaps an aircraft or in space, and indeed the ABM treaty prohibits those things. But before you can do boost-phase missile defense even against a small country like North Korea from ships, you need to develop an entirely new missile -- one that's twice as fast as any missile the Navy has. You need a bigger, more powerful radar than exists currently on Navy ships. This bigger, more powerful missile won't fit in the launch frames of a Navy cruiser, and so you need a new framework for those new missiles, which haven't been developed yet themselves. When all is said and done, you need new ships to put all this stuff on. ...
So when you look at the time that it takes to develop these new missiles, to develop the new radar and to build the new ships, you're talking about many, many, many years. And the ABM Treaty would not prevent that developmental work from going forward.
So you don't buy the argument that the ABM Treaty had to be scrapped right now in order to move forward with research, testing, development even of national missile defense?
That's correct. The Russians had indicated to the United States that they were flexible about development and testing; that their concern was deployment. ...
I think the administration didn't like the treaty, and just wanted to get rid of it.
And national missile defense was a convenient cover?
That's how it looks.
How do you explain this rush to deploy that was going on during the Clinton administration and is continuing during the Bush administration?
It is strange, because there isn't a real threat. People postulate that there could be. People postulate that North Korea could develop ICBMs. People postulate that Iran or Iraq could do that. But they haven't yet, and the intelligence community has said so in their formal estimates of the threat.
[Editor's note: See this map of the major missile powers for more information.]
On the other hand, there is a threat from short-range missiles. There is a threat from Scuds and other short-range missiles that our troops see overseas. After all, a little over ten years ago, 28 U.S. soldiers were killed in Saudi Arabia from a Scud attack and about 100 wounded. So that's a real threat.
So I would say that the priority ought to be going to developing short-range missile defenses for threats like that overseas. There isn't a threat yet for intercontinental ballistic missiles.
The definition between short-range theater missile defense and national missile defense has become more blurred. Why is that, and why is that perhaps not a correct way of looking at it?
The Clinton administration treated the various missile defense programs discretely, so there was the Army's PAC-3 and THAAD, theater air defense system, which were designed for use overseas. Similarly, the Navy had a short-range and a medium-range missile defense program. Those were treated discretely also. Then finally ... defending the whole of the United States from ICBMs was separate still.
The Bush administration has pushed them all together basically under one name -- missile defense. That has confused the debate about missile defense, and blurred the distinction between these various systems and the priority they ought to get.
[Editor's note: See this overview of "theater" missile defenses.]
... It sounds to the public as if ... it's all the same thing. That's not the case?
Yes. It's very much more difficult to shoot down an ICBM fired from some country toward the United States ... than to shoot down a short-range missile in some theater of war overseas. Shooting down an ICBM with a hit-to-kill missile is like hitting a hole-in-one when the hole on the green is going 15,000 miles an hour. Doing it when there are decoys is like hitting a hole in one when the hole's going 15,000 miles an hour and the green is covered with a bunch of other holes that look just like the one you're supposed to hit.
The theater systems that work against short-range missiles don't have that problem, because basically they're defending themselves. So they know what the target is. The enemy missile, the Scud, let's say, is coming at our soldiers overseas. They know they're the target, and so they're defending themselves. ...
Many people feel that if you can solve the problem of shooting down short-range missiles like Scuds, that that's sort of the same thing as shooting down an ICBM. ... In fact, it's a whole quantum jump. It's a factor of 10 more difficult, just much more challenging. It's because the ranges are so much longer, the speeds of the missiles are so much faster, 15,000 miles an hour. The size of the target that you're trying to hit is quite small. So you're trying to hit within inches something that's thousands of miles away and moving very fast; whereas when it comes to a Scud attack, it's maybe only a few hundred miles away, and quite a large missile relative to the area you're trying to defend.
As I understand it, ... theater missile defense is what [the Joint Chiefs of Staff] have been supporting all along.
That's correct, and the reason is because they know that there's a real threat from short-range missiles overseas. We've already experienced that. They don't see the threat as being anywhere near so urgent for ICBMs.
When you were in the Pentagon, would you hear that? ...
Yes, and it's been reported in the newspapers and in various books. Bradley Graham [of The Washington Post] wrote about it. The one thing the chiefs would have liked ... [was] to have had some missile defense capability against accidental or unauthorized launches from Russia or China. They saw that as a more likely occurrence than, say, North Korea or Iran or Iraq attacking us, both out of the blue. ...
Secretary of Defense Rumsfeld has said that he wants the Missile Defense Agency to produce. Talk to me about the testing rate that will be necessary.
These intercept tests, national missile defense intercept tests, are very complicated. They cost almost $100 million apiece, and because they're so difficult to do, they've been taking a fairly long time to do one to the next.
The administration is trying to shorten the time between tests, and they absolutely need to do that if they're going to succeed in my lifetime. If these tests take a year apiece, which some of them have from one to the next, and there are about 20 developmental tests that have to be done before realistic operational testing can even begin ... that's 20 years. Then the realistic operational tests would add a few more years after that.
Now if you can do them at twice that rate, if you can do them every six months, then you could do it in 10 years. If you could do them every four months, let's say, you could do it in maybe seven years, you'd be ready for realistic operational testing. But that still could be a decade overall before you were ready for deployment. So we're talking about very long time scales, unless the rate of testing can be sped up tremendously.
Then you need to do that for all three phases -- for the boost phase, for the midcourse and for the terminal. Again, there's about 20 tests that would have to be done in a boost-phase system ... so that could take seven or 10 or 20 years, depending on how fast you did it. Same thing for terminal defense systems. So all in all, you could be talking about 70 or 80 or 100 tests -- because some of them won't be successful, some of them will have to be repeated -- that will have to be done, all in all, for a layered system. ...
Do you think the President and the Congress are being told this starkly?
I've not seen anybody say that. General Kadish has said that this is very difficult. He has said we need to be patient, walk before we run, crawl before we walk. But I think that there are members of Congress who have unrealistic expectations when it comes to missile defense.
Most military equipment can take 10 or 15 or 20 years or more to develop. The F-11 Raptor, modern new fighter, has been in development for at least 20 years. The M-1 tank ... has been in development for over 20 years. Various Navy ships and helicopters and so forth have all taken on the order of 15 or 20 years. So if these relatively easy defense efforts can take 20 years, missile defense is probably going to take that long or longer.
And yet, isn't our foreign policy now being formulated as if this were something that we will have within a few years?
It seems to be that way, yes. I don't understand that. The Russians seem to understand it, however. I've seen where Russian generals have said publicly that the United States isn't going to be able to do this for 20 years, and they're probably right.
So that's why they are reacting calmly?
... We really haven't discussed the cost, other than to suggest it would be a lot.
It's very difficult to estimate the cost of missile defense because there are so many different pieces -- land-based, at sea, in aircraft, in space. They're all quite expensive, and the administration has said that it's not going to pick a particular architecture for the foreseeable future.
So it's very difficult for cost estimators to get their arms around this if there isn't even an architecture. It's like estimating what your house is going to cost, and you haven't even talked to the architect yet. The Congressional Budget Office did estimates recently where they looked at various pieces of missile defense. They said in the introduction, "Don't add up these numbers, because there's overlap between some of the pieces, and there's things we haven't included at all." Nevertheless, many people did add it all up, and it came to $238 billion, which is a lot of money. ... That would include the development and the operation of the system for 10 or 20 years. ...
[Editor's note: See "The Budget: What Will It Cost?" for more.]
When some of the technical difficulties are pointed out to people -- the difficulties with boost phase, for example, and a large country -- the answer comes back: Space.
Yes. Shooting down enemy missiles from space is also complicated. One of the ideas that's been proposed is a space-based laser, a huge very high-power laser that would float around out in space and would shoot down enemy missiles from there. That's not something I expect to ever see happen. The technical challenges of building large, high-power lasers on the ground are tough enough. But doing it in space would be really impractical.
Another idea is what's called "brilliant pebbles," ... small smart satellites which are floating around in space and which could be sent down to hit an enemy missile sort of as it went by. You would need perhaps a thousand of these small satellites for this job, because the ones that are on the wrong side of the earth don't help. So you need to have some that ... are always in the right place. If you're going to defend against all these different countries all around the world ... you need lots of satellites. So that also would be a very difficult development, because you've got to get all those satellites in orbit. ...
Talk to me about what's happening with the so-called airborne laser.
The airborne laser has had to delay its schedule about two years recently. They had hoped to be able to do a demonstration of the airborne laser against a tactical target like a Scud relatively soon, but now it looks like that will be 2005 or later.
It's a very difficult program. The laser would be carried inside a 747 jet. There's a set of optics that allows the laser beam to go out the nose of the jet and try to shoot down an enemy target. Currently they don't have a laser that has enough power for that, and it wouldn't fit in the 747 anyway. But they hope to be able to develop a laser which would have enough power to shoot down an enemy missile -- at first, tactical missiles and then perhaps later, ICBM missiles. But it's very difficult development, and is many, many years away.
One of the issues with the airborne laser is you need to get fairly close to the target. The laser can't propagate forever through the atmosphere on its way to the target. Atmosphere has a tendency to spread it out, spread out the beam. So you have to get fairly close, and a big 747 loaded with high-power laser equipment would make an inviting target to, say, North Korea. Even if they didn't have an ICBM or other kind of missile that it could shoot down, they might enjoy shooting it down just because it was such an inviting target. ...
Even more difficult would be to try to do that in space and a space-based laser, and that's something that, as difficult as the airborne laser is, the space-based laser is altogether another thing and probably will never happen. ...
Another [thing] that we haven't talked about is that the offense always has the advantage.
Yes. It's a truism of battle, I guess, that the offense has the advantage. It's also true when it comes to missile defense. The United States is an open country. You can read in Aviation Week and in other defense journals how U.S. systems work and the enemy knowing that can then design their offensive system, their ICBMs or other missiles, to take advantage of the way that our particular missile systems are designed. So that will always be a problem for missile defense. ...
So what do you say to people who say, "Any national missile defense is better than none?"
We have missile defenses today. If we learn that North Korea is building an ICBM, we're going to blow it up on the ground. We're not going to wait until they finish that and then launch their missile toward the United States. ... We will know if somebody starts to put together the pieces of a huge missile, just as you can see at Cape Canaveral in Florida when we start to put the shuttle together. ...
So in that situation, as you said, we have a missile defense. It's just not this system that we've been talking about today.
Right. Pentagon briefings for national missile defense show Plexiglas domes over the United States and we imagine that enemy missiles will bounce off this Plexiglas dome like hail off a windshield. We'd all probably love it if such a defense were possible. It simply isn't in the cards. ...
If all these arguments ... against really the possibility of a national missile defense are so cogent, how do you explain its staying power?
Well, Senator Sam Nunn has said wisely that it's a question of theology over technology. People who believe in national defense believe in it quite passionately, and think that we can do it; and there are aspects of missile defense that I think we will be able to do.
But the impermeable shield defending against all missiles of all ranges, defending our friends and allies all around the world as well as ourselves everywhere against all adversaries with a layered system-- I don't see that happening in my lifetime.
... The political debate more and more seems to presume that it's possible. Is there a danger in that?
Well, I suppose there's no harm in trying. I think the most important thing is that members of Congress who are deciding to spend money on various kinds of missile defenses, that they be realistic and understand what the difficulties are so that they can adequately weight the various choices that they have to make. Should they be spending money on this, [or] on a new bomber? The B-52s that have worked so well in Afghanistan aren't going to last forever. ... They need to understand what the difficulties are, so they can better assess how to authorize and appropriate funds. ...
If the president were asking you when would we be able to intercept with any confidence a theoretical ICBM from North Korea, what would the answer be?
In a very limited way, if there were only a few North Korean missiles, a handful or less, and if they didn't have decoys, we might be able to do it in 10 or 15 years. ...
We have actually two kinds of missile defense already, today. We have the ability to shoot to blow up enemy missiles on the ground before they are ever launched. That's what we would do if North Korea ever tried to build and launch an ICBM toward the United States.
But another kind of defense that we have [is] our diplomats, like former Secretary of Defense Bill Perry. In 1999, he made what must have been an exhausting series of trips to North Korea. But he was quite successful, and got them to agree to stop the work that they were doing on long-range missiles and the associated testing.
Dr. Perry himself wouldn't say that North Korea was no longer a threat at all. But they were certainly no longer the same threat as they had been after he did his work. That kind of diplomacy is very important. ...
The missile defense programs that the Department of Defense is pursuing today are the most difficult things they've ever tried to do. ... Some people compare it with the Manhattan Project to develop the atom bomb. But in many ways, that was much more focused and more tractable technically than parts of missile defense are. Of course, the Manhattan Project was carried out under the exigencies of a world war. ... [It] was about building a single thing, an atom bomb.
Missile defense is about defending, as Secretary Rumsfeld has said, all ranges of threats -- short range, medium range, long range, intercontinental ballistic missiles; defending the United States, our friends and allies all around the world in all kinds of battlefield situations that we might be able to imagine -- with land-based, sea-based, aircraft-based and space-based systems. So when you put all that together, it's a very diverse set of programs, and very complicated. ...