If there's one thing no country is immune to, it's pressure. For the US, France, and the UK, that means pressure from the populace to dismantle their nuclear arsenal, but for the...less democratic nations, it means pressure from other nations. Leaving them out of international events like the Olympics. Boycotting their goods. If it worked for ending apartheid in South Africa, it can work, as long as it is applied in a way that isn't aggressive.