The post-American world will be many things, but multilateral isn't one of them. There will be no world government and international organizations will be good for little except sucking up the last drops of wealth and prestige of the United States. It will be a chaotic place with everyone out for themselves. …..
The end of the Pax Americana also means the end of international law. Instead of a post-American world ushering in a stable multilateral order, it will revert back to a chaotic Lord of the Flies situation in which no single power will predominate, but in which any country or militia that can seize a piece of land or a natural resource will go ahead and do so. For the first time in generations, the First World may wake up to discover that it is once again living under Third World rules.
Daniel Greenfield in The Shape of a Post-American World