Ukraine gave up its nuclear weapons.
Simple possession of them would very likely have avoided a conventional war costing them hundreds of thousands of lives.
Recent American rhetoric about Canada is an exact mirror of Putin's "Not a real country" foreshadowings.
Canada could build even a few small nuclear weapons in months, for a tiny fraction of our F-35 budget. And short-range drone delivery systems that would have many other uses. But never have to use them.
But, should we?