A Conflict in Space Could Go Nuclear. It Doesn’t Have To.

Satellites quietly support both military operations and everyday life. We rely on them whenever we navigate with our phones, check the weather, or tap to pay at a store. Militaries rely on them for surveillance and communications critical to conventional and nuclear capabilities. Increasingly, militaries also see space as a warfighting domain in its own right.

This military dimension is getting harder to ignore. In 2024, U.S. officials warned that Russia is developing a new space-based anti-satellite weapon that could carry a nuclear warhead, which Russia has denied. Placing a nuclear weapon in orbit would violate the 1967 Outer Space Treaty. Russia subsequently vetoed a UN Security Council resolution that would have reaffirmed the treaty’s ban.

The latest development came on September 14, when Air Force Secretary Troy Meink told a conference audience that the United States has “on-orbit space control weapons capable of defending the joint force against hostile adversary action.” It marked the first public acknowledgment of a capability long assumed to exist. Meink did not say what the weapons are, how they work, or when they were placed in orbit, but a Space Force spokesperson later commented that the weapons can be used for both offensive and defensive purposes.

NTI President and CEO Christine Wormuth, former Secretary of the Air Force Frank Kendall, and Paul Dean, NTI’s vice president for the Global Nuclear Policy Program, explored the implications of these recent developments and how they relate to nuclear risks during a panel discussion at NTI on November 4.

“Not long ago, it was almost taboo to call space a warfighting domain,” Wormuth said. “Today, governments say so openly. The question now is whether we can keep that competition from becoming a pathway to nuclear escalation.”

Why This Is a Nuclear Problem

Satellites rarely do just one job. The same satellites that support conventional military operations often help warn of missile launches and carry orders to nuclear forces. Much of U.S. nuclear command and control depends on satellites for early warning, tracking, and communications. As Dean noted, nuclear deterrence is “inextricably tied up in outer space security.”

When nuclear and non-nuclear missions share the same networks, it gets harder to know which satellites a rival considers essential to its nuclear forces. In a conflict, an attack meant to disable a satellite’s conventional role could also inadvertently degrade an adversary’s early warning capabilities or damage its nuclear command links. In that case, what one side intended to be a conventional move, the other might interpret as an impending nuclear attack.

What Governments Can Do

Increase official dialogue. Much of the danger stems from uncertainty about which satellites matter to the other side’s nuclear forces and how an attack on them would be interpreted. The only way to reduce that uncertainty is through dialogue. A good place to start would be to develop a shared view of which kinds of conflict in space are most likely to cross a nuclear threshold. Governments could also agree to treat certain satellites that support nuclear forces as off-limits, or as Kendall put it, “Don’t touch these because you might start a nuclear war.”

Build on existing norms. Establishing agreed rules of the road would make it easier for states to distinguish between routine activity and a threat, a distinction that is even harder to make when relations are already tense. In 2022, the United States led 155 countries in supporting a UN General Assembly resolution against destructive direct-ascent anti-satellite missile tests. Similar efforts could set basic standards for behavior in space.

Keep nuclear weapons out of orbit. In addition to being illegal, placing a nuclear weapon in space would be the most dangerous development of all. Reports that Russia is developing one make this more than a hypothetical concern. Such a weapon would be indiscriminate, wiping out GPS and the timing signals that so much civilian infrastructure depends on. It would also create a dangerous “use it or lose it” dynamic, pushing the country holding it toward early use in a crisis. As Dean explained, such a weapon is “very likely to be used in a conflict because if you don’t use it, the other side will take it out.” Reinforcing the Outer Space Treaty’s ban should be a top priority. Spacefaring nations, including the United States and China, could lead a global campaign to reaffirm the treaty, while governments work to develop practical ways to verify that space launches are not carrying nuclear devices.

No major power has an interest in an unintended nuclear war. Weapons are now in orbit. The guardrails are not. The time to build them is before a crisis, not during one.