What were the prospects for world peace at the end of World War II?
If, by world peace, you mean a situation in which there would be no war or conflict anywhere, I would say there was no realistic prospect whatsoever.
At the end of WWII, it was not very likely at all that there would be another big war any time soon. The end of WWII saw most of the major countries of the world in very bad shape from the fighting. Only the US could really have had the wherewithal to have any chance of fighting another big war soon.
However, there were many things that made it almost inevitable that there would be conflicts. First, there was the issue of communism and the Soviet Union's desire to create a strategic buffer for itself. These issues led to civil wars in places like Greece and Korea (since the Korean War was more or less a civil war). Second, there were issues of colonialism and the desire of various colonized countries to be free. This led to conflicts around Southeast Asia.
So, if world peace is a situation with no huge wars, the prospects were good. If world peace is a situation with no conflicts at all, the chances were extremely remote.