Michael KreponArms Control Implications of the War in Ukraine (III): Missile Defense

Quotes of the week:

“The world is full of abandoned meanings.” – Don DeLillo, White Noise

“I think the International Criminal Court could be a threat to American security interests, because the prosecutor of the court has enormous discretion in going after war crimes.” – John Bolton

As a result of Russia’s war of aggression against Ukraine, theater missile defense deployments have become increasingly important, even as national missile defense deployments remain hopelessly outmatched against advanced long-range missile capabilities.

Non-wonks: Generally speaking, theater missile defenses are designed to counter ballistic missiles of less-than intercontinental range. They do not protect vast expanses of territory. National missile defenses are configured to protect the entire homeland against missiles that can be launched from close in or from afar.

Qualifiers are in order. For some small states – Israel being the prototypical case – there really is no meaningful distinction between theater and national missile defenses. And in some cases, multiple theater missile defense deployments could provide notional national defenses, at least against a subset of missile threats.

As theater missile defense interceptors become more capable, they will be able to cover more territory against attacking missiles launched from greater distances. Air defenses are also becoming more capable. While designed primarily for use against hostile aircraft, they might also have modest success against some types of ballistic missiles.

While the distinctions between national and theater missile defenses are bound to narrow in the future, they still matter for major powers with large land masses to defend. These distinctions also matter for states that have many “high value” targets separated by substantial distances.

For these countries and others with serious security concerns, the nature of nuclear deterrence isn’t static. Competitors habitually seek advantage and seek to avoid disadvantage. That’s why nuclear-armed states worry so much about missile defense deployments that could devalue missiles in which they have invested so heavily.

Because the Soviet Union was deeply concerned about U.S. technological advantages, Washington could leverage a freeze on new silo construction and then deep cuts in Soviet offensive missiles by talking up the necessity of national missile defenses.

The Johnson and Nixon administrations originally planned to deploy national missile defense interceptors and radars at over a dozen sites. This was more than sufficient to end the silo construction boom in the Soviet Union. In return, the 1972 Anti-Ballistic Missile Treaty limited each superpower to two fields of missile defense interceptors totaling two hundred per side.

Ronald Reagan’s Strategic Defense Initiative was even more disconcerting to the Kremlin leadership, until Mikhail Gorbachev figured out that he could ground it by accepting deep cuts in Soviet missiles. These reductions would have been inconceivable without the ABM Treaty in force.

Never mind that U.S. national missile defense deployments faced hopeless odds against a country like the Soviet Union which possessed many missiles carrying multiple warheads as well as “penetration aids.” Pen aids are designed to confuse radars needed to direct missile defense interceptors to incoming warheads.

Never mind that the radars needed for effective intercepts were soft targets that couldn’t be defended. And never mind that schemes to place missile defense interceptors in space could also be foiled by far less expensive countermeasures – such as trailing space-based interceptors with much cheaper space mines.

Despite all of the above, Moscow was willing to pay — and pay twice — in the coin that mattered most to Washington to prevent U.S. national missile defense deployments.

Even after these reductions, it’s harder now to defend the U.S. homeland against missiles than it was when the ABM Treaty was negotiated five decades ago. Or after George W. Bush decided to withdraw from the ABM Treaty in 2001 and, for good measure, to dispense with negotiated agreements concluded in the Clinton administration to demarcate permissible theater missile defense capabilities.

Why have missiles become even harder to intercept? Because more countries have more of them, and because there are more new types of missiles that can reach their intended targets in different ways. “Old fashioned” long-range ballistic missiles can still get though. They are now supplemented by modern cruise missiles that follow routes designed to foil ballistic missile defenses. Then along came increasingly stealthy cruise missiles. If this weren’t enough, hypersonic glide vehicles and maneuvering hypersonic glide vehicles are now part of the equation.

President Dwight Eisenhower and his successors have spent over three hundred and eighty billion dollars on missile defenses, according to Stephen Schwartz’s tally. And yet there are more ways for national missile defenses to fail than ever before.

So, why keep spending money for them? Because after 9/11, no President can concede complete national vulnerability to missile attack. It’s possible, but far from certain, that interceptors might work against missile threats that aren’t highly evolved, like those of Iran and North Korea. But their missiles will also become more advanced. And rushing to deploy interceptors for homeland defense — as Presidents Richard Nixon and George W. Bush did — is guaranteed to produce ineffectual defenses.

All of this speaks to minimalism when it comes to national missile defenses. In contrast, U.S. investments in theater missile defenses have never had greater value. This trend line will continue to rise because of Russia’s war of aggression against Ukraine.

One reason for the added military and political utility of theater missile defenses is because missile threats situated nearby U.S. allies and partners continue to grow. Another is that some missile threats are crude instruments of terror, designed to terrorize city dwellers. A third is that advances in theater missile defense capabilities are likely to be more pronounced than advances in national missile defense capabilities.

A fourth reason — of particular note to those of us who believe in arms control – is that theater missile defenses can serve as a substitute for the forward deployment of U.S. tactical nuclear weapons in cases where deploying them is (a) politically unfeasible, or (b) unhelpful, or (c) unwise.

Before returning to Putin’s war against Ukraine, let’s set the clock back further, to his decision to blatantly disregard the Intermediate Nuclear Forces Treaty by authorizing the flight testing of a ground-based cruise missile beginning in 2008. The INF Treaty, signed by Reagan and Gorbachev, zeroed out land-based missiles with ranges between 500 and 5,500 kilometers.

Putin had his reasons, among them President George W. Bush’s clear signaling of intent to place Ukraine and Georgia in the queue for NATO membership. Another possible reason was that Putin presumed (rightly) that NATO would not be willing to counter his treaty violation by deploying new ground-based missiles. Putin would thus gain some comparative advantage, at least in his own mind.

Except that NATO states now have an alternative means to link arms with the United States without deploying land-based INF missiles. Poland and Romania have done so by hosting theater missile defense capabilities on their soil.

Now fast forward to the war in Ukraine, which has, so far, prompted a high degree of NATO cohesion, even after Donald Trump’s four-year-long shocking and awful campaign against alliance solidarity. The more Putin and his retinue engage in nuclear threat making against NATO — including threats directed against the addition of new Scandinavian members — the more Moscow invites additional theater missile defense deployments.

Theater missile defenses can be overwhelmed, just like national missile defenses. And in cases where missiles have extremely short flight times, theater missile defenses could have negligible military utility. But not all threatening missiles have short flight times. And in the case of allies and partners of the United States, theater missile defenses do not have to demonstrate a high degree of military effectiveness to convey political messages about U.S. support and alliance cohesion.

The primary problem with theater missile defense deployments, as with national missile defense deployments, is that states that don’t like them can add more offensive capabilities to make sure that they don’t work. This leaves states facing nuclear threats in a bind: they can either choose not to offend the threatener, or they can choose to defend themselves in ways that demonstrate steadfastness against nuclear threats.

One way to respond to nuclear threats is to seek nuclear weapons in some form, perhaps through sharing arrangements. An alternative approach to reassuring allies and partners is through theater missile defense deployments, more permanent basing of allied conventional forces, and the like. Whatever the threatened state chooses, the opposing threat level is likely to increase. These unwelcome choices have become more pronounced as a result of Putin’s war against Ukraine.

If added increments of theater missile defenses take the pressure off increased stockpiles and deployments of tactical nuclear weapons, this tradeoff warrants serious consideration. If added increments of theater missile defenses come with additional production and forward-deployed tactical nuclear weapons, that’s a different calculation.

During the Cold War, arms control agreements succeeded over time in breaking the cycle of increased nuclear threats and an intensified offense/defense competitive dynamic. Many of these agreements were discarded in favor of freedom of action after the Cold War ended. Today’s headlines reflect prior choices.

Arms control agreements now have very poor prospects. Prospects for revival depend on when leaders of the United States, Russia, and China concurrently conclude that unwelcome offensive and defensive trend lines need to be reversed.

Trend lines point to growing inventories of cruise and ballistic missiles. It is becoming harder to distinguish between those armed with nuclear or conventional weapons. Missile defense interceptors are also likely to grow in number. As I write in my book, one way to limit all of the above is to bundle them together.

It’s worth considering a trilateral arms control regime that counts all conventional- and nuclear-armed missiles beyond a certain range. In such a control system, Washington, Moscow and Beijing would be allowed the freedom to mix within agreed limitations between offense and defense, between conventional and nuclear, and between theater and national missile defenses.

Impossible, you say? Far too delicate a balance of terror? A terribly bad idea? Way too soon to even contemplate? All of the above? Granted, an agreement of this sort is far beyond visual range. Just as it was inconceivable in the 1970s for the U.S. Navy to consider relying less on aircraft carriers in light of the emerging cruise missile threat.

Then again, the inconceivable has a way of happening — sooner or later.


  1. Ken Brociner (History)

    Michael- That was an extremely clear discussion of a very complex topic. I feel as if I just sat through a master mini-course on the the various calculations and strategies involved in missile defense systems. Let’s hope (and pray) that if any of these systems are ever used that it will involve non-nuclear weapons!