Some claim that we are a nation under God, but since (as all major religions believe) God is omnipresent, omniscient and omnipotent that means that all nations must be under God, and that he knows what's going on in them.   Why then, if all nations are under God, are the people here (relatively) more free and more prosperous than those in some other countries, like Darfur or North Korea?   Maybe it's because, as you've mentioned, they have no document (like our Constitution  -  imperfect as it is) to which they are willing to adhere.