Russian space nukes would be a sword of Damocles over our heads

The prospect of a Russian nuclear weapon in space, as reported in the American press on Wednesday 14th February, has colossal strategic implications for global security and the United States’ (US) defence posture in particular. Nuclear detonations in space produce powerful electromagnetic pulses that can wipe out large numbers of the satellite systems that have become so vital to the functioning of modern society and, particularly, to Western militaries.

It must be stressed that the exact nature and status of this new threat are not yet completely clear at the time of writing. The New York Times initially wrote about a ‘space-based nuclear weapon’ directed at US satellites. Then PBS News Hour suggested that the new Russian weapon might be ‘possibly nuclear-powered’, and configured for electronic warfare in space. The Washington Post’s first reaction left all options open, by mentioning both an anti-satellite space-based ‘nuclear weapon’ and the use of ‘directed energy to disable satellites’. 

The most recent information comes from CNN, which says that according to three official US sources the capability in question is indeed a nuclear weapon but that it is ‘not yet in orbit’. The implications of the worst-case scenario, where Russia acquires the capability to orbit and detonate nuclear bombs in outer space, must be considered. 

In legal terms, such a step would deal a mortal blow to the 1967 Outer Space Treaty (OST), the bedrock of today’s international space regime. The OST specifically prohibits the placement of weapons of mass destruction in space. By such an action, Russia would be effectively collapsing the only global framework for space arms control and security, with incalculable consequences for space governance going forward.

From a military point of view, Russian space-based anti-satellite nuclear weapons – there is no telling how many there could be, over time – would act as a sword of Damocles over all spacecraft in Low Earth Orbit (LEO), where the vast majority of military and civilian satellites operate. Any nuclear explosion in LEO would not only destroy satellites in its line of sight: more and more satellites would continue to be disabled as they orbit through the radiation field in subsequent days. 

The best real-world evidence for this comes from the Starfish Prime atomic test conducted by the US over the Pacific in 1962. About a third of all the few satellites active at that time were eventually damaged or rendered inoperable by the nuclear detonation that took place at an altitude of 400 kilometres – where the International Space Station orbits today.

The most chilling aspect of this threat is that it makes perfect sense from a Russian point of view. Moscow’s military is much less reliant on space power compared to those of the West, particularly the US. America depends on space support to conduct operations at global distances with a highly-advanced, networked military whose smart weapons systems need to communicate via satellites, and whose planning and tactical engagements rely heavily on space-based intelligence. 

Furthermore, the contribution of Western-provided space services to Ukraine – from communications through Starlink to intelligence data through both military and civilian remote sensing satellites – has been essential to Ukraine’s war effort. This even drove Moscow in October 2022 to designate Western satellites supporting Ukraine as legitimate targets.

But on the ground, in contrast to Ukraine’s experience, the Russians might well have concluded after two years of war that they can do without significant space support for their own operations. This stark asymmetry is ripe for exploitation if the Russian regime calculates it has much less to lose than its foes by taking space out of the military equation to even the odds.

There is no defence against the brunt of an in-space nuclear attack. It is mostly a game of yield and distance.

There is no defence against the brunt of an in-space nuclear attack. It is mostly a game of yield and distance. High-value military satellites are hardened against radiation and can survive at closer ranges to the explosion than normal spacecraft. But if several weapons are used at different altitudes, there would be no escape.

The politics of this development are especially troubling. By actually placing nuclear weapons in orbit and gaining the ability to effectively neutralise much of the West’s warfighting capacity at a stroke, Putin would be opening a new strategic front in his confrontation with the West. It would be a highly escalatory step, and potentially the prelude to a full-scale war with the North Atlantic Treaty Organisation.

It is highly likely such a move would trigger a space version of the Cuban Missile Crisis, the stand-off between the US and Soviet Union over the latter’s deployment of nuclear missiles on Cuba which threatened world thermonuclear war. Now, as then, the new threat suddenly presented by Moscow could not be tolerated, yet in the present case, removing it through military action – trying to neutralise the Russian spacecraft in orbit – could lead precisely to the crippling detonation which must be avoided. 

Even if CNN’s reporting is correct and Russia’s assumed nuclear space weapon is not deployed yet, its political effect would be nearly as grave and destabilising. It would also perhaps be even better suited to Putin’s goals of forcing a negotiation with the West at a time when Ukraine is on the backfoot, the Middle East is in crisis and Taiwan is under increasing pressure. 

The diplomatic costs of a Russian space nuke would be very high, because this time, unlike the energy crisis triggered by Putin’s 2022 invasion of Ukraine, disrupting space would have major global effects including on his close partners – not least on the People’s Republic of China which also is deeply invested in the space domain. 

Indeed, if anything stands against the unbearable prospect of Russian nuclear weapons in orbit, it is the likely veto from Xi Jinping, General Secretary of the Chinese Communist Party, on any such plans by Putin. Regardless, the Russian president may be willing to go ahead anyway, but this is unclear currently. In any event, it would seem that the long-feared moment when a ‘space Pearl Harbour’ becomes possible is now in sight. If confirmed in its worst outlook, the gravity of this threat cannot be understated.

Gabriel Elefteriu FRAeS is Deputy Director (Defence and Space Policy) at the Council on Geostrategy.