I agree with you that high unemployment leads to civil unrest, and you can only hope that trustworthy individuals can fill the power vacuum that leads to. It's not a completely hopeless situation, you've got groups like Podemos in Spain pushing forward, and I think the likes of Corbyn in the UK and Sanders in the US represent the interests of the working class and middle class of their respective countries (even if Sanders doesn't get elected, he seems to be inspiring more people to get involved in the political process to push for the things that benefit the majority).

As for isolationism leading to war, I think this I think has been blown out of proportion. Of course in extreme examples it can happen, but I'd suggest at most we'd be looking at Australian-style economic protectionism rather than North Korean-style isolationism.