  As conservatives used to be fond of saying, the US should not be the policeman to the world. I agree. But I believe that the world does need a policeman. E.g., Serbia, Rwanda, Uganda, Afghanistan, Iraq, Haiti. So, who? The UN would be the answer, if it were capable of bilateral force. I believe that the answer is an expanded, empowered NATO. Ultimately, nations will have to give up sovereignty in order to solve global problems. Perhaps a confederation would be a good approach. Someone needs to write a global constitution. 
