Easily imaginable: every country with big enough nuclear arsenal could be viewed as a country holding the fate of the world in its hands.
But since there can be multiple such countries at the same time and since no one has stopped developing arms/tech even further - I wouldn't call it a paradox when one nuclear country feels threatened by another group of both nuclear and non-nuclear countries coming closer and closer to its borders.
But since there can be multiple such countries at the same time and since no one has stopped developing arms/tech even further - I wouldn't call it a paradox when one nuclear country feels threatened by another group of both nuclear and non-nuclear countries coming closer and closer to its borders.