I agree that the U.N has no real teeth. however, the main problem is that the U.S ensures that it's own agenda is followed as much as possible, whilst brandishing the threat of Veto power if it isn't.

Also, the U.N head is usually the one who is supported by the U.S, otherwise he is not re-elected, as in the case of old boutros. By the way, how many had acually heard of "yankee Moon' before he was elected?