[lapcat]

> We are on the brink of world war three and the UN's only reason for existing is to prevent that from happening again, but instead of doing its job

What do you think the UN is supposed to do when one of the permanent members of the Security Council with veto power decides to go to war?

The foundation of the UN depended crucially on the temporary alliance between the United States and the Soviet Union during World War II. This alliance quickly fell apart though, leading to the long "Cold War", which arguably still exists, apart from a short lull in the 1990s. When the US and Russia are at odds, it's almost impossible for the UN to perform its function. The veto power of the permanent Security Council members ensures that the UN has no enforcement mechanism over those individual nations. This was by design of the founding nations: the United States and Soviet Union never gave the United Nations the power to constrain the United States and Soviet Union.

Having said that, World War III not inevitable. There were only 20 years between WW1 and WW2, while we've gone more than 75 years since WW2, so maybe the UN has done its job?