I’m going to make a point here, and I hope I am wrong, but I don’t think I am. If America falls apart, I think it will be the first one, not the only one. The influence America exerts on much of the rest of the world is huge, and the pressures on many other nations to follow any collapse with one of their own would be difficult to stop. Not just influence culturally, but economically, including but not limited to agriculture. Removing the agricultural influence provided by America alone will be devastating for much of the world (including non-agrarian parts America).