Nukes are an instrument of last resort, but you don't want to get to the point where that is your only option. And it is possible that technical advances in missile defence may blunt this advantage.

Being able to prevent friendly (and even neutral) countries from being bullied or going over to the dark side is also important because ultimately the best defence against rising autocratic forces is to ensure a broad alliance of friendly, democratic countries who are secure against interference by unfriendly regimes.

If a country like the USA can have its elections manipulated, how vulnerable might smaller democracies be?