From the other countries perspective, it is a tremendous power imbalance.
The fact that any city of your country could be destroyed by an invading force in 3 seconds at zero cost for the invaders is for sure not very reassuring.
That actually happened in the US territory with native people, they were exterminated by outsiders with superior technology leaving almost not trace behind. This was costly for the invaders because the technology difference being great was not that great.
Right now, with the US(spaceX) able to put a rocket in any part of the world in 30 minutes with a nuclear head, the power imbalance is extreme. They do not have to risk a single life to destroy an entire city or nation!!
This is something that no country on earth should tolerate and they will not tolerate if if they have enough technology.