Toad if you mean by prestige and authority that UN is supposed to bully the occupants and become occupyers, you've misunderstood of the whole peacekeeping operation. That's more like the role the US has taken. Probably you think everyone else should act the same way.
The idea behind the UN should be that the combatants would honor and respect the voluntary effort the peacekeepers are putting for thier country. The whole system is based on trust really. The means to achieve the goal is _peaceful_ intervention. The biggest problem is naturally how to act when someone breaks that trust, like it has happened often lately.
It's therefore possible that the principles behind the UN action were unrealistic and naive. Probably a lot stronger actions are necessary to make any real difference in the cases where true criminals are in question. Criminals who do not value human rights or the value of life.
That kind of criminals can be dealt with only in one way - surgical removal. But as long as the leadership of the world is full of sissies and treehugging politically correct ladies, the countries will never unite to form a true force that would dictate the rules and supervise them effectively.
Hitler was close to achieve that situation.
That fact remains no matter what you think of the ideology behind his actions.
