The Ukraine War and nuclear sharing in NATO

Abstract Russian nuclear sabre-rattling following the 2022 invasion of Ukraine has reinvigorated debates over NATO deterrence. One of its key components—nuclear sharing—has been in place since September 1954, but support for it within the alliance has varied over time. Indeed, although Belgium, Germany, Italy, the Netherlands and Turkey host American gravity bombs on their territory, there were fears during the 2010s that some of them would follow Canada, Greece and the United Kingdom's example and withdraw from the scheme. By examining why and how NATO's nuclear-sharing arrangements have changed since inception, we argue that they consistently serve deterrence, signalling, alliance cohesion and burden-sharing goals, which make them hard to dismantle. However, we also demonstrate, through our survey of post-Cold War policies, official statements and public debates, that there is more room in a low threat environment for political contestation within host states. Accordingly, nuclear sharing requires a high threat environment to escape domestic opposition, which effectively returned in 2022, cementing the nuclear status quo.