The Golden Dome Missile Defense System, With Todd Harrison

LINDSAY:
Welcome to the President's Inbox. I'm Jim Lindsay, the Mary and David Boies Distinguished Senior Fellow in U.S. Foreign Policy at the Council on Foreign Relations. This week's topic is the Golden Dome Missile Defense System.

With me to discuss President Donald Trump's proposal to build a multi-layered defense system to protect the United States against ballistic, hypersonic, and cruise missiles is Todd Harrison. Todd is a senior fellow at the American Enterprise Institute. He has written prolifically over the years on defense budgeting, the defense industrial base, and space policy. His assessments of the Golden Dome proposal include "How Much Would a Space-Based Missile Interceptor System Cost, and Does It Make Sense?" and "Is Trump's Golden Dome a Brilliant Idea or a Gilded Boondoggle?" both of which can be found on the AEI website. Todd, thank you for coming on the President's Inbox.

HARRISON:
Thanks for having me.

LINDSAY:
Todd, let's begin with what precisely it is that President Trump has proposed to build. My understanding, it's essentially a space-based defensive system, but give me a sense of what it's trying to protect against and how it would do so.

HARRISON:
Sure. Well, we don't know a lot of the details yet. Most of what we know is what was in the executive order that came out back in January, and what that says is they want to build a robust homeland air and missile defense system that could defeat attacks from peer, near-peer, and rogue adversaries.

LINDSAY:
Okay, can you translate that into English? What do we mean when we say peer, near-peer adversaries?

HARRISON:
Rogue adversaries, we typically think of as North Korea and Iran, but peer or near-peer, that is a clear reference to Russia and China. So he wants a missile defense system capable of protecting against very large-scale attacks that Russia and China could potentially launch against the United States. So that is probably the biggest difference in this system compared to what President George W. Bush and administrations since then have been working towards. But an important part of it that they outlined in the executive order is they want to include space-based interceptors that are capable of hitting missiles in their boost phase. That won't be the only part of it. As you said in the introduction, it's supposed to be a multi-layered system, but that also is a key distinguishing feature of this iteration of homeland missile defense.

LINDSAY:
Todd, I want to put a question up front here and that is how similar is Donald Trump's Golden Dome proposal to Israel's Iron Dome? I mean, I think a lot of people have seen the success of the Israeli system in recent attacks launched by Iran. Are we talking about similar sorts of defensive systems or are there fundamental differences?

HARRISON:
Some very fundamental differences. I mean, obviously the biggest difference is the amount of area covered. Israel is very small. The size of one of our small states within the United States, and what Trump is talking about is covering the entire homeland. The other big difference is the types of threats it's intended to protect against. Israel and their Iron Dome system—and things like David's Sling and other parts of that—they're primarily focused on relatively short to medium range threats, things that can be launched by Hamas, Hezbollah, or as far away as Iran. Their system is not designed to protect against very long range missiles like ICBMs, sub-launched ballistic missiles, or hypersonic missiles of any type.

LINDSAY:
What does that matter, Todd?

HARRISON:
Well, the threats that the U.S. homeland faces are very different. It's not as if we have a terrorist group like Hamas or Hezbollah on one of our borders, launching very low cost, not so sophisticated rockets and drones into our territory. The main threats to the U.S. homeland are very long range, much more sophisticated threats and the types of defenses you need against those are very different and require a lot more sophisticated technology.

LINDSAY:
How much does it matter that the Israeli system in terms of its successes, has been going up against missiles with conventional warheads as opposed to nuclear warheads?

HARRISON:
Well, the consequences of missing are obviously going to be a lot higher if it's a nuclear warhead. But in terms of trying to shoot down the missile or destroy the warhead once it's released from the missile, it really doesn't make a difference whether it's conventional or nuclear, the interceptor is going to work the same. The difference, of course, is going to be the consequences, and as I said before, nuclear armed missiles tend to be on long range ballistic missiles, and those go to much higher altitudes and move at a much faster velocity, which makes those long range missiles regardless of their warhead, much harder to intercept.

LINDSAY:
So let's talk about the boost phase aspect of this proposed system. Can you perhaps explain what do we mean when we talk about boost phase interceptors and what are the pluses and minuses of trying to hit missiles in the so-called boost phase?

HARRISON:
Yeah, so the boost phase is the period of a missile where the booster rocket is firing, right? It's before it releases the warhead. So it's from the time it's launched to the time it burns out and releases its payload. Now, for a solid propellant missile, which is what folks typically use, and we know Iran has done, North Korea has been developing them, solid propellant boosters burn faster. And so their boost phase is typically around three minutes. And so that gives you a very narrow window of time in which you can hit it.
Now, why do you want to hit something in the boost phase? The main reason is because... Well, two reasons. One, because that booster is burning very hot and very bright, that's easy to see and track and hone in on. So it's a bright glaring target to try to hit, but also when it's in the boost phase, that's before it can release multiple warheads and decoys and other things that could interfere with your ability to hit it. And once the booster burns out, if it releases multiple warheads, now you have to hit each one of those warheads rather than just a single missile. That's why it would be great to be able to hit a missile in the boost phase, but it is a very difficult thing to do just given the amount of time you have.

LINDSAY:
And so I'd imagine in that case, Todd, if you're going to have a boost phase system, it essentially would have to be automatic. You don't have time for a human in the loop to make decisions.

HARRISON:
Well, you would have very little time at best. So if you imagine a launch scenario where Iran launches a solid propellant ICBM at the United States, and it's going to burn for about three minutes, it might take us around thirty seconds to detect that launch, especially when it's low to the ground, it's harder to see, but to detect that launch and start to establish a track and then be able to say, "Hey, this is an ICBM and it's headed on this trajectory towards the United States." So, thirty seconds or so to detect and track, and then how do you make that decision to fire an interceptor? That might take, if you've got humans in the loop at all, even if you've pre-delegated that decision authority down to the commander in charge of that unit, it still might take you fifteen, twenty, thirty seconds for someone at the console to call the boss over and say, oh my gosh, look what's happening. Should we fire on it?
They're probably going to want to consult some other data sources and then quickly make a decision. So the best I could imagine is probably a thirty second decision space. Well, now we've burned up one minute of the boost phase. We've only got two minutes remaining, and that becomes a very hard shot.

LINDSAY:
So as you look at the boost phase from just a technical feasibility point of view, how feasible is it to have a system that can attack missiles in the boost phase against large salvos? Again, as you laid out the beginning, Todd, the is to be able to provide a defense of the United States against attacks from peers, which means in theory, large salvos.

HARRISON:
Right? So that's where it becomes challenging, especially if you want to do it from space, because a ground-based system, if you've got your interceptors on the ground, they have to be relatively close. They got to be within a range where they can make it and intercept that missile within about two minutes. But a ground-based system is sized based on the total threat that your adversary poses, whereas a space-based system is sized based on how many missiles they could launch in one salvo. And so you have to be able to do that in every little pocket, every cell of coverage around the earth has to have that maximum capacity.

LINDSAY:
Because you have to protect against both land-based ICBMs, but also submarine-launched ballistic missiles.

HARRISON:
Exactly. And your space-based interceptors, they also have to be close to the missiles that are launching, which means they have to be in low earth orbit. And if you're in low earth orbit, you are constantly moving relative to the surface of the earth. So the satellites are whizzing around the earth all the time, moving in and out of coverage. And so what that then means is for a space-based interceptor system, ultimately you are limited by the range of each interceptor and the range of each interceptor is limited by the amount of time it has between you when you give it the signal to fire and when that booster burns out, and as I said before, that's probably only going to be about two minutes, a hundred and twenty seconds, that determines your fly-out time.
And then calculations that I've run on this, if you assume that each missile has a certain amount of performance and how much they can accelerate during that time, I assume they can get about six kilometers per second change in velocity, which is fairly aggressive if you compare it to other studies, then your fly-out range is pretty limited, and you're going to need about five-hundred interceptors in orbit just so you always have one within range.
So it's about a five-hundred to one ratio, five-hundred interceptors in orbit will give you one that's always within range of any potential site on average. Now, if they actually were to launch a missile, we're probably going to put two interceptors against it just to be sure, right? Because they're never going to be perfectly effective. So now I need a thousand interceptors on orbit, so I can always have two within range to intercept a single missile. If I want to be able to intercept a hundred missiles, then I need two-hundred interceptors in range, which then means I need two-hundred thousand on orbit.

LINDSAY:
That sounds very expensive, Todd, unless the cost of interceptors has plummeted in recent years,

HARRISON:
Well, it does not scale well, as you can see from that example that the numbers become astronomical. Now, of course there's going to be some efficiencies, some economies of scale if you're going to be buying interceptors in that huge quantity. But the bottom line is it's not going to be cheap. If you want to do boost phase intercept from space, we're talking something if you really want to do the scale of protection they're talking about for a Russian or a Chinese or a Russian Chinese simultaneous launch, worst case, you are talking something that's going to go into the trillions of dollars over the next twenty years or so.

LINDSAY:
And I would imagine though, if you scaled down the ambitions of the system and it was merely designed to stop a North Korean attack or an Iranian attack, and again Iran does not yet have intercontinental ballistic missiles or warhead to match the demands on a space base boost phase intercept system will be much smaller because you have a limited geographical area from which the missile is going to fly or put differently they don't have sea launched ballistic missiles.

HARRISON:
Right. And if you look back at... People have cited this CBO study that was recently updated, and the press has miscited it over and over again. The CBO study did look at the cost of space-based interceptors. It's a study from about twenty years ago, but they did update the launch cost, but in that study, they only looked at the cost of an interceptor system that would be capable of hitting one missile at a time and only if it's launched from North Korea or Iran. And the advantage of just focusing on North Korea and Iran is you don't need global coverage. You can put your satellites in an inclined orbit, so they're only covering from forty-five degrees latitude north down to forty-five degrees latitude south. It has to be symmetric like that, but that would cover Iran and North Korea. That would be great. That only covers half the earth though, and it covers virtually nothing of Russia and big parts of China are above that as well.

LINDSAY:
And it would still be very expensive.

HARRISON:
It would still be very expensive, but that does scale down your cost quite a bit if you limit that coverage.

LINDSAY:
Now, Todd, we've been talking at this point or until this point about space-based interceptors trying to take out missiles in the boost phase. What about mid-course attacks? Would that change the calculations at all?

HARRISON:
It does. It changes it for the better and for the worse. So it changes it for the better because in the mid-course phase, you may have fifteen or twenty minutes for your interceptor to fly out and reach its target.

LINDSAY:
Also more time for humans to make decisions.

HARRISON:
A lot more time, a lot more decision space. But the big improvement in the design of the system is you don't need nearly as many of the interceptors in orbit because they can each cover a much larger area. So a mid-course defense system—in a paper that I did looking at sizing a mid-course system—if you want to have a hundred interceptors within range of any launch, then you would only need about two thousand interceptors in orbit. So much better scaling ratio there. Now, the downside of mid-course is, as I said before, once the booster burns out, it can release multiple warheads and decoys. So you've got the challenge of telling the decoys from the real warheads, which can be hard when they're coasting through the vacuum of space. But then also you may have a dozen warheads that get released and you have to hit those individually, whereas you could have hit the booster missile with one interceptor, you now may need ten interceptors to hit all the warheads that came out of it.

LINDSAY:
So as you look at this and sort of thinking through the reactions such a system is likely to trigger, how likely do you think it is that if you could make this theoretically successful, that the pressure on the Russians or the Chinese would be simply to increase the size of their arsenals or to develop better decoys, more warheads on a missile, things like that?

HARRISON:
Well, yeah, I think it's certainly going to change the incentives that both Russia and China have. I don't think it changes much with regard to North Korea and Iran. If anything, it may discourage them because they have no hope of being able to field enough missiles to overwhelm a system that was sized for Russia or China. But for Russia and China, I think they're going to find themselves in slightly different positions.
One, Russia is in an arms control agreement with us, not that they care too much about following the terms of it, but there is that. And Russia, I think would have a much more difficult time scaling the size of their nuclear forces. I say that because they have a difficult time maintaining their nuclear forces today. I think the most likely investments for Russia are probably going to be into decoys and putting multiple warheads on the missiles they already have. I think for China, China already seems to be on a crash course to build out their nuclear forces. Could they go faster? Probably. But nothing is constraining them already in building out their nuclear forces. So I don't know that we would see that big of a change in their behavior. I think we would just see them continue to build.

LINDSAY:
What about the argument that a system like this based in space would in itself be vulnerable to attack? I've seen speculation that the Russians are building a missile that they would detonate a nuclear warhead in space, and that would create an electromagnetic pulse and that would disable a system of the kind that Trump administration is talking about as well as ruining thousands of commercial satellites.

HARRISON:
There's always been that threat of Russians detonating a nuclear device in space. They've had that capability for many years. They've tested that in the past. They've actually detonated nuclear weapons in space. So has the United States. We all realized pretty quickly in the early sixties what a bad idea that was for the space environment. We actually detonated a 1.4 megaton weapon at an altitude of four hundred kilometers, which according to records now, we believe it actually ended up frying the electronics on about a third of the satellites in space at the time, including the UK's first ever satellite. We destroyed it inadvertently with our test. But there's a reason that neither us or the Russians or Soviets back then have engaged in any more of that testing is because it is not productive for either of us. It's counterproductive to our own interests.
I think Russians detonating a nuclear weapon in space again, that is a suicide attack. That is something they would do absolute desperation. Could it be devastating for an interceptor system like this? Well, I would fully expect that this type of system would be shielded against electromagnetic attack, as are many of our other military satellites today, our missile warning satellites, our protected communication satellites, they are all designed to be shielded against an EMP blast and continue operating. I fully expect that these interceptors would be shielded as well. Now the main victim of that would be commercial satellites, which are not shielded, would be very vulnerable in lower orbit to the radiation environment that this would kick up.

LINDSAY:
We've talked a lot about space-based systems designed to take out ballistic missiles, Todd. What we haven't talked about are drones which don't go into space, and there's been a lot of concern given what we've seen in the Middle East, what we've seen in Israel about the proliferation of drone warfare. How do drones fit into this idea of a golden dome?

HARRISON:
Well, that is one of the big unknowns. The executive order seems to cast a wide net in terms of the threats they want to protect against, which would include drones, cruise missiles, other things like that. Obviously, space based interceptor, they don't help you at all with these types of threats that are low down in the atmosphere. They can't reach that low. They would burn up, so you'd need totally different types of defenses.
That's where it could start to overlap more with things that we've seen used in Israel and in Ukraine. Patriot batteries and some counter drone systems, drones that go out and attack other drones, some directed energy systems, high-powered lasers, high-powered microwave that can be used against drones as well. These are very different types of capabilities, and in theory, they will also be part of Golden Dome. And one of the things we've seen in the way the administration has been talking to industry about Golden Dome is they've been talking about it in terms of three layers and underlayer defense. That would be things like this that would protect against drones, cruise missiles, and their coverage would be over a very local or regional area. Upper layer defenses are things like THAAD, which is used to hit ballistic missiles in their terminal phase, and then over layer defenses is the space layer of things.
So it seems like they are thinking of it in those different layers, but what we don't know is what's the mix of capabilities and how much emphasis are they going to put on drone and cruise missile defense versus long-range ballistic missile defense.

LINDSAY:
Todd, how would they even size a drone threat? And I think most people would operate in the assumption that Canada's not going to fire drones at the United States, Mexico would not fire drones at the United States, that the real issue would be drones coming off ships along the American coast, Pacific and Atlantic. They're both very long. Would it become prohibitively expensive to build systems that could take out a drone attack?

HARRISON:
That's a great question. And I don't know that there is a good way to size a counter-drone system because these things could be launched in swarms of hundreds or thousands, and you have to be able to protect against those types of quantities in a very localized area. And so probably you're going to have mobile defenses that will be a big part of this. And where you start to see a threat emerge, or if there are very sensitive targets you want to be sure to protect against, you just locate your protections there. But I don't think this is something where you could provide coverage over the entire continent. I think you would just do it in pockets here and there. But yeah, I mean, this is a real threat because it's not just ships that can launch them. It could be cargo containers that have been smuggled into the United States. That is precisely what Ukraine did to Russia, and they were able to take out parts of Russia's nuclear forces, bombers while they were sitting on the ground.

LINDSAY:
Well, that would make the system even more expensive if you have to cover the interior of the United States, even if you were just to focus on major military bases or economic assets.

HARRISON:
It absolutely would. And you would have to then prioritize what are the major military installations, ports, other key infrastructure, population centers, special events, what gets covered and what doesn't? That would be a very difficult and political set of decisions.

LINDSAY:
Todd, can we shift to the question of the impact of Golden Dome on strategic stability? I think your argument that many of these ideas are technically feasible, there's a real question whether they can scale at an acceptable price to the budget, whether we can afford it. What do you think the consequences of pursuing Golden Dome as it's envisioned will be on Russian and Chinese behavior?

HARRISON:
Yeah, I think the truth is we can't know with any certainty before it happens. Unfortunately. It's going to be a wait and see. So far they've come out and had some pretty strong statements against it that is to be expected. Of course, they're not going to like this, but how do they actually respond? And one of the papers I've written about this, I posit that it is entirely possible that President Trump sees this whole Golden Dome system as trade bait, as a way of luring Russia and China into a multilateral arms control agreement. He has made very clear that's what he wants to do.

LINDSAY:
This is the bargaining chip theory of building weapons.

HARRISON:
Exactly. And just have the credible threat that we're going to do this. And it will not negate, but it will undermine a lot of their investments and their nuclear deterrent forces and bring them to the negotiating table and see if you can get some big treaty. I think it is increasingly unlikely that that would actually work.

LINDSAY:
Why do you think it would be unlikely to work?

HARRISON:
I don't think Russia and China are actually going to negotiate in good faith over something like that. I think that he may get them to come to the table and they may start talking and they may start indicating, oh yeah, sure, we can reach an agreement and they'll just run out the clock. Because I mean, quite frankly, it would be very logical of Russia and China to be skeptical that the United States will follow through with Golden Dome and pass this administration. Given the amount of funding required, and given just the name of the system itself being so closely associated with the personality of this particular president, they may feel some confidence that this is not going to be real, that this will not actually ever materialize as Trump is saying right now.

LINDSAY:
Todd, I often hear the opposite argument being made. That while the Chinese and the Russians may be skeptical about the ability of the Trump administration to make this system on the timeline and at the budget the president has proposed, I think it's three years and a hundred and seventy-five billion dollars, something like that, that nonetheless, the Chinese and Russians have to operate in the assumption, we might call it the worst case assumption, that this might actually go forward, that it will impact or threaten potentially their arsenals. And as a result, we're going to have basically crisis instability. That we're going to create incentives for the Russians or the Chinese to act in ways we don't want them to act in crises. What do you make of that argument?

HARRISON:
Yeah, I don't think that's really played out. If anything, I think air and missile defenses, and I will caveat this with the obvious statement that we've never seen it at the scale being talked about in Golden Dome.

LINDSAY:
Right. Because the existing American ground based interceptors, what? Forty-four interceptors and two bases in California and Alaska,

HARRISON:
And that really only is targeted at North Korea. It could not hit much from Russia at all. But I would say look at what we've seen with missile defenses and their role on conflict stability in the Middle East where Iran launched huge waves of ballistic missile and drone attacks against Israel. Israel knocked down more than ninety percent of them. The damage inflicted was very minimal compared to what it could have been, and Israel then had the time and space to formulate a more rational response. Imagine how that would've played out—

LINDSAY:
But wouldn't you think it would be different if you're talking about instances of nuclear tipped missiles because at a ninety percent interception rate, you still would lose your society.

HARRISON:
Exactly. So I think deterrent still holds, right? They know that they can still hold us at risk, and they know that we can hold them at risk with our own missiles. So I think deterrent still holds.

LINDSAY:
Because I think the opposite argument would be that you would create an incentive, take your Israeli case, to hit Iran before the Iranians could hit Israel. And the same thing with same could play with Russians and the Chinese views the United States.

HARRISON:
Yeah, I mean, I think the way we've seen it play out though is Israel's been able to, in a conventional fight, absorb the hit, shoot most of it down, very minimal damage elsewhere, and then take the space to formulate a more coherent response. I think had Israel not had those air and missile defenses, and the vast majority of those missiles had made it into Israeli territory and probably would've hit some targets and done some real damage, I think that the political leadership would've had very little decision space. They would've had to have responded to a much higher degree and much more immediately than they did. And so I think that air and missile defense systems in general, they just give you more breathing room in a conflict. And I don't think in the terms of nuclear stability that it will change much in terms of deterrence because our adversaries know they can still hold us at risk, something will get through, and then they know the reason not to do that is the same reason it's been since the end of World War II is the threat of a massive retaliation.

LINDSAY:
So why wouldn't that logic apply in reverse, Todd? Why isn't that American military leaders, political leaders realize that this system is never going to be perfect? The missiles will get through. We're not going to provide people with a real defense. We're not going to render nuclear weapons impotent, obsolete. I will note this is really the third iteration of a big push for missile defense. I'm old enough to remember Sentinel and Safeguard, late sixties, 1970s, Ronald Reagan in the eighties with the Strategic Defense Initiative. Those spent a lot of money and produced very little at the end of the day. Why would this be different?

HARRISON:
Yeah, I think it very much may fall into that same trap. I would agree with you there, but I think there is a more compelling case for the defense against rogue or inadvertent launches wherever they may come from, because you can't deter that. And I think there is a compelling case for drone and cruise missile defense for a conventional attack. If we got into a shooting war with China over Taiwan, and we are hitting targets in mainland China, it's fair game for them to be hitting targets in the mainland U.S., right? With conventional means of attack, right? The fact that today we have virtually no defenses against that in the continental United States is kind of a glaring hole in our deterrence posture with China.

LINDSAY:
Well, that gets us back to the bigger question being, are we preparing for the most likely and most devastating threats? I think you're quite right on the issue of how drones could be used. There's also the issue of how cyber attacks could be used to disable a range of the modern conveniences that we experience, really putting the country in a very bad place. And I'm not sure that we are necessarily assessing the real threats and the way you might do it if you were sitting down and trying to do it in a sort of synoptic logical fashion.

HARRISON:
No, I think that is a very good point that we've got a lot of different threats to the mainland that we need to worry about. This is one of them, but it is certainly not the only one, but it is the one that we have an executive order about, and Congress just appropriated 24.4 billion to start this effort without any real of what it's going to be or what precisely it's going to defend against and in what capacity. So I think that is a real decision policymakers need to grapple with is what is the relative emphasis we want to place on this type of defense versus other types of defenses. And I would add to your list, in addition to cyber, defense of our space systems. If you want to have a systemic debilitating attack against not just the U.S. military, but the global economic engine that runs the world, space becomes a very attractive target, and China and Russia have been building out a full suite of counter space capabilities precisely to hold those assets at risk.

LINDSAY:
That is a very big challenge that this administration and its successors are going to need to find a way to confront. But I don't know that there's any simple answer for that challenge, Todd.

HARRISON:
There isn't, of course, right? And that's where I come down at the end of the day, is nothing you can do is ever going to buy absolute security. So the real question is how much risk are you willing to accept?

LINDSAY:
Well, that is a perfectly fine place to end our conversation. I'll close up this episode of the President's Inbox. My guest has been Todd Harrison, Senior Fellow at the American Enterprise Institute. Todd, thank you very much for joining me.

HARRISON:
Thank you. It was a pleasure to be here.

LINDSAY:
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