Gen. Stephen Whiting, the commander of U.S. Space Command, recently made waves when he publicly discussed a major threat that America’s newest military branch recently war-gamed — that of an adversary detonating a nuclear weapon in space.
At first blush, the scenario seems far-fetched. In truth, though, it is a real possibility.
More than a year ago, in February 2024, House Intelligence Chairman Mike Turner (R-Ohio) was already raising the alarm that Russia could place a space-based nuclear device into orbit. That possibility was later confirmed by the Pentagon.
The White House grasps the danger. A December 2025 Executive Order on Space Superiority directs the country’s relevant agencies to create “a space security strategy that accounts for United States interests in, from, and to space” and “a technology plan for detecting, characterizing, and countering potential adversary placement of nuclear weapons in space.” That strategy, moreover, is expected as soon as June 16.
This public call to action is notable. It marks the first time an unclassified document has publicly directed a response to a nuclear weapon in space. It also reflects the gravity of what is an increasingly plausible threat. After spending several months conducting a deep dive into this subject, we at the American Foreign Policy Council have come to the same ominous conclusions. Space-based nuclear weapons are a serious matter, and one that deserves the very highest level of national attention.
Talk of a nuclear detonation generally triggers visions of cities being destroyed and mushroom clouds. The effects differ when a detonation occurs at a high altitude. While explosions near space, or in space, may not have immediate destructive effects here on Earth, they can prove equally devastating. Even a relatively small nuclear device, detonated at the right place in low Earth orbit, would have a catastrophic impact on U.S. and allied interests.
That is because, while space itself is enormous, the vast majority of modern spacecraft (nearly 90 percent) are in low Earth orbit, most of them satellites. Both the American and the global economy rely on these systems for everything from the functioning of the Internet to aircraft navigation and ship tracking, at a cost of billions of dollars daily, and trillions annually.
Moreover, our intelligence agencies and the U.S. military rely extensively on satellites to detect the movement of adversary ships, aircraft and tanks; to track ballistic, hypersonic and cruise missiles; and to communicate with our overseas forces. And in the near future, advanced capabilities will allow the U.S. Space Force to globally track everything that moves in the skies or on the ground in real time, in addition to all weather across the entire globe.
A space-based nuclear explosion anywhere could be damaging, but one in low Earth orbit would be crippling. If a nuclear weapon were detonated above this range, in a medium, higher Earth or geostationary orbit, the blast effects would basically only destroy satellites within a few kilometers.
But a nuclear weapon detonated in low Earth orbit would be far more devastating, because it would interact with the Earth’s magnetic field. The resulting radiation would be so strong, it would basically destroy everything in low Earth orbit in under a week’s time — leaving more than 10,000 derelict satellites on intersecting orbits with no way to avoid each other. The resulting destruction would be massive. A nuclear detonation there would truly be a weapon of mass destruction.
Worse still, repopulating those space assets after a detonation would be extremely complicated. We lack a stockpile of military (or civilian) satellites that are radiation-hardened, that could serve as replacements for the dead ones in orbit. Nor do we have proven technology available for deployment in space to reduce the harsh radiation. Finally, we have not yet invested in the technologies that would allow us to build build the satellites needed to replenish low Earth orbit quickly and efficiently.
By next week, the Department of Defense and intelligence community should have an actionable plan to deal with this gargantuan problem — or at least the start of one. Congress needs to stand ready to resource it. Moreover, as we have recommended, it should catalyze investments in space traffic management models, commercial “what if” agreements, radiation remediation technology, radiation-hardened replenishment, and long-term investments in an in-space industrial base above the threat.
Putting such a plan in place is a necessary start. But it will necessitate political will and resolute action on the part of the U.S. government. Otherwise, we risk being left in the dark.
About the authors:
Peter A. Garretson is a senior fellow in defense studies at the American Foreign Policy Council, where Richard M. Harrison is vice president of operations. They are the authors of a new report on Space Nuclear Weapons.