While only nine nations possess nuclear weapons, more than 30 others support their retention and potential use, including by claiming protection from an ally’s so-called “nuclear umbrella”.

All members of the North Atlantic Treaty Organisation (NATO), for example, have publicly endorsed nuclear weapons. Several even host US nuclear bombs on their territories – including Belgium, Germany, Italy, the Netherlands and Türkiye – and provide the aircraft and personnel needed to drop them. Belarus has a similar hosting arrangement in place with Russia.

Some nations share intelligence for the purpose of nuclear targeting, or allow nuclear-armed ships to transit through their waters and dock in their ports or nuclear-armed aircraft to enter their airspace and refuel at their airports.

All such acts of complicity perpetuate nuclear dangers and undermine disarmament efforts.