The nuclear deterrent works because of MAD. If only one nation had the capacity for nuclear weapons, there's a strong case to be made that we'd be living in a totalitarian world state or at the very least vassals to the dominant state.
Israel is not using theirs on Gaza either.
Imagine what Trump would do. He is already trying (and mostly failing) to strong-arm all his allies today.
Yet, it never happened. Actions matter.