Space Nukes Are Bad

Space nukes may sound like a plot device too outlandish for even a Roger Moore–era James Bond movie, but real life can sometimes outpace fiction—especially when it comes to Russia and the bomb. According to U.S. officials, Russia is developing yet another new type of nuclear weapon. This one is specifically designed to attack satellites. After being launched, it could remain in orbit for some time—weeks, months, or perhaps even years. If detonated, it would wreak “indiscriminate” destruction on the satellites that orbit closest to the Earth.

As insane as this concept may sound, it makes a certain amount of warped sense for Moscow. Russia is conventionally weak and knows it—now that its two-week war against Ukraine is in month thirty-one, the rest of the world knows it too. To compensate, Moscow has long sought the capability to attack the satellites on which the U.S. military depends. For much of the post–Cold War period, its interest focused on nonnuclear antisatellite weapons. However, the United States is trying to obviate them by deploying thousands of small satellites for military purposes. Ukraine demonstrated the effectiveness of such constellations through its use of Starlink, which wasn’t even developed for military purposes. In response, Russia has revived its interest in nuclear-armed antisatellite weapons.

In a conflict, Russian President Vladimir Putin would likely view detonating space nukes as risky—very risky—but it might appear to him as substantially less risky than the alternatives. Of course, a space nuke would destroy a bunch of satellites besides those being used by the United States and its allies to fight Russia. Chinese and Indian military satellites, as well as numerous civilian satellites, would all be annihilated. Moreover, nuking satellites en masse would cause almost unimaginable disruption to the lives of the people on Earth’s surface. But, for Putin, these consequences might seem much less costly than either losing a war to the United States—remember what happened to Saddam Hussein and Muammar Gaddafi?—or detonating a nuclear weapon in the Earth’s atmosphere.

The danger of space-based nuclear weapons isn’t just that Moscow might actually use them. It’s that Washington knows Moscow might actually use them. As a result, the United States might attack Putin’s space nukes before he can push the button—which, in turn, might incentivize Putin to jab his finger as fast as he can.

The View From the Oval Office

This is a bit head-spinning. To understand the problem, imagine you’re the president of the United States. You’re fighting the good fight against Russia. A few months back, the Ukraine war escalated dramatically, and the United States got drawn in. Now, American troops are poised to liberate Crimea. Your popularity is soaring. An election is coming up, and you feel good about it. The strains of your planned second inaugural address are reverberating around your head.

Into the Oval Office comes a four-star general, looking concerned. “We assess with high confidence that the Russians have just launched three space-based nuclear weapons,” the general says. “They’re now in orbit. We have no evidence that Putin has decided to detonate them yet, but he could do so. At. Any. Moment.”

The general emphasizes how much damage space nukes could do to the United States’ command-and-control system, one result being that the war would take longer and cost many more American lives than expected. Your mind immediately goes to the question of what you should do if Putin pushes the button. Should you use nuclear weapons in response? If you do, how will Putin respond? You reluctantly concede to yourself that fighting a nuclear war is part of the job description of the commander in chief of the United States’ armed forces, but it’s a responsibility you desperately want to avoid.

Fortunately, the general informs you, the intelligence community assesses that these three weapons are the only nuclear-armed antisatellite weapons that Russia has available. Moreover, the United States can destroy them—the most reliable way being to collide missiles into them. We did it before, the general tell you. Back in 2008, the United States used a ballistic missile defense interceptor to shoot down an ageing American weather satellite. On your order, the general says, we’ll do it again. You can knock out Russia’s space nukes without using nuclear weapons yourself.

The general acknowledges that there are downsides to the plan—mostly that the attacks would create debris that could damage or destroy many other satellites, including American military satellites. The general emphasizes, though, that the detonation of nuclear weapons in space would cause much more damage. You certainly don’t relish the idea of shooting at Russian nukes, but compared to letting Russia use them, the potential problems don’t seem so bad.

At the same time, a Russian general is briefing Putin in a bunker deep under the Kremlin. “Sir,” he says. “Our nuclear charges are in orbit. But I want to remind you that the Americans can shoot them down. At. Any. Moment. If you want to use them, sooner would be better.”

Putin nods, “I will consider it, but as I said before, I launched these weapons mostly to scare the Americans. Detonating them is a last resort.” And then he pauses, before musing aloud, “You know, if the Americans think that I’ll detonate the weapons, they’d have good reason to attack them as soon as they can. Maybe I should push the button . . . ”

In the Oval Office, the same thought in reverse occurs to you. “If Putin thinks that I’m planning to attack his space nukes, he’d have a pretty good reason to detonate them. So maybe I should attack them now . . . ”

You give the order. To your relief, the operation is a success. Russia’s space nukes are pulverized. The Situation Room is all high fives. An hour or so later, however, Russia launches a handful of nuclear-armed ballistic missiles and detonates them in space, frying innumerable satellites. The general later explains that Russia had only three nuclear weapons that were designed to be placed in orbit and lurk there prior to being used. Nuclear-armed ballistic missiles can’t loiter in that way, but they’re just as effective at destroying satellites if detonated while in space.

Even so, your main concern now isn’t about your dead satellites; it’s the fact that you’re now in a nuclear war. Granted, it’s not the worst kind of nuclear war—no one on Earth was killed directly by Russia’s nuclear explosions. Whether it will remain that way . . .

Reducing the Risks of Crisis Instability in Space

There’s more than an element a tragedy in this series of events. You’d rather not attack Putin’s space nukes. He’s rather not nuke your satellites. Each of you, however, feels pressure to act because you’re worried that the other side will act first. In the world of nuclear strategy, such pressure is known crisis instability.

Crisis instability is not a new idea. Nuclear strategists have been arguing for decades about whether a state might use its nuclear forces because it feared they were vulnerable to attack by an enemy’s nuclear forces. However much the problem of crisis instability induced by vulnerable nuclear forces worries you, the risks created by vulnerable satellites and space nukes should concern you more—much more. Moscow would be more likely to detonate a nuclear weapon in space than it would be to use one in the atmosphere. Washington would be far more likely to use a nonnuclear weapon to destroy a Russian space nuke than it would to use its nuclear forces to destroy Moscow’s.

So what can the United States do to mitigate this danger?

If U.S. diplomats aren’t already explaining, in great detail, to spacefaring nations—friend and foe alike—just how much damage a single Russian space nuke could do to their satellites, they should do so. Moreover, they should suggest that foreign heads of state express concern to Putin directly. He needs to know that the international repercussions from the use of such weapons would be dramatic.

The United States should also make its command-and-control satellites more survivable. This isn’t easy, but there is one glaring omission in current U.S. plans that should be addressed. Satellites in the Proliferated Warfighter Space Architecture—the planned U.S. system comprising thousands of military satellites—will not be radiation hardened. Such hardening cannot enable a satellite to survive the blast from a nearby nuclear explosion, but it can enable those further away to withstand other effects, including the electromagnetic pulse and radiation. The good news is that the Department of Defense plans to update the design of satellites in the Proliferated Warfighter Space Architecture regularly—precisely so new capabilities can be added. As a matter of urgency, it should examine the benefits and costs of hardening all future satellites.¹

Arms control also can help manage crisis instability by reducing the threat to vulnerable assets. Moscow has no interest in talking right now, and its record of violating agreements causes understandable concern in Washington about entering new ones. Even so, the United States can and should prepare for possible future negotiations. To this end, the intelligence community and the State Department should be tasked to assess whether a prohibition on space-based nuclear weapons could be defined and verified.² The Departments of State and Defense should assess what the United States should be prepared to give up in return for such a prohibition.³ To be clear, a ban on space-based nuclear weapons should be reciprocal and apply to both Russia and the United States; even so, it would benefit the United States more than Russia. It therefore would have to be paired with a second reciprocal ban that favored Russia to ensure a mutually beneficial package.

None of these options are panaceas. If Putin’s back were against the wall in a war against the United States, he might not worry much about how third parties would react to his detonating a nuclear weapon in space. Hardening satellites is expensive and provides only partial protection. The political prospects for arms control are poor. Nonetheless, because of the risk of crisis instability, Russia’s space nukes are uniquely dangerous. It is better for the United States to respond with half measures than not at all.