The short answer is IMO It starts at home, not abroad.

It is good to see this - shortened - question being asked here. We have often seen posts on the failure of governance as a or the significant factor in small wars occurring, but not IIRC the demise of the nation state that has so dominated world politics since at least 1815 (in Europe).

I vividly recall IIRC "Sammy" Finer's writing on the ungovernability or overload of government of the UK in the late 1970's, probably as the power supply was reduced by a long labour strike. His article is not to hand, so a search is needed and has failed.

In my search I found a speech by a current, if low profile Labour politician, David Miliband; it includes this:
The latest British Social Attitudes Survey reports that in the last 25 years the percentage of people saying that politicians put the national interest before party interest has fallen from 47 per cent to 20 per cent. The percentage who say it is not worth voting has risen six fold (to 20%).

(Shortly after) To cap it all, no one, not the Government nor Opposition, not the Bank of England nor the FSA, warned the public about the danger of the biggest economic crisis for eighty years. No wonder people are sceptical.
Link:http://davidmiliband.net/speech/spea...isis%E2%80%99/

Since the 1970's, IMHO in most Western democracies, we have seen the power of the state to be effective at home shrink for a number of reasons. Today it is the "fiscal cliff" so I shall stick with public finances being more unpredictable, with vested interests becoming the national interest as political power changes.

Last week I read 'The age of turboparalysis: Why we haven’t had a revolution' by Michael Lind, unknown to me:http://www.spectator.co.uk/features/...urboparalysis/

It opens with:
....the condition of the world continues to be summed up by what I’ve called ‘turboparalysis’ — a prolonged condition of furious motion without movement in any particular direction, a situation in which the engine roars and the wheels spin but the vehicle refuses to move.

The greatest economic crisis since the Great Depression might have been expected to produce revolutions in politics and the world of ideas alike. Outside of the Arab world, however, revolutions are hard to find. Mass unemployment and austerity policies have caused riots in Greece and Spain, but most developed nations are remarkably sedate.
The article's bio line is:
Michael Lind is the author of Land of Promise: an Economic History of the United States and a columnist for Salon.