I don't, on principle, answer "what did the world think" questions because the world is big and I don't really know which countries you actually care about and the amount of information available on how country X thought about the bomb is often quite limited, especially civilians (polling was still in it infancy). It's just not something that can be answered. At least not by me!

For the American public, whose reactions were fairly well-studied at the time and have been studied since, you can see this reply of mine from awhile back, where I summarize some of the big issues and polling data we have. The short answer is a mixture of excitement and, upon surrender, exultation. But always coupled with a looming fear of and uncertainty about what would come next, if atomic bombs were part of the new world order.