I haven't read Francis Fukayama but I have read Paul Kennedy's "The Rise and Fall of the Great Power in which he wrote--"The United States now runs the risk ,so familiar to historians of the rise and fall of previous Great Powers, of what might roughly be called "imperial overstretch" that is to say, decision-makers in Washington must face the akward and enduring fact that the sum total of the United States' global interests and obligations is nowadays far larger than the country's power to defend them all simutaneously"
