I must admit that I am not particularly knowledgeable of the history of Argentina, but "gave" seems an odd word to use given the long history of military dictatorships, oligarchy, political centralization, and suppression of indigenous people. You also talk about the driving force towards centralization being wealth distribution, but the military dictatorships have been primarily right-wing/fascist/corporatist and even the article you link about Americans being in favor of a putsch mentions that the majority of those in favor of a putsch are Republican, i.e. not in favor of *fairer* wealth redistribution. Europe has a long history of social democracy, growth, and stability, so I'm not seeing the connection between redistributive policies and decline. Otherwise, I agree with the basic premise that the concentration of power in the United States is a serious threat to democracy and stability.