Europe is much, much stabler, at least right now. I follow the political polls in Europe and what you say is... mostly not true.

> AFD in Germany in the 15-20% range

According Wikipedia, no poll ever has given AFD more than a 15%, with the vast majority giving it around a 12.5% (https://en.wikipedia.org/wiki/Opinion_polling_for_the_German...). Even if AfD would get to 20% (which it's very far away from their predicted results) it's very unlikely they would get to the government.

> Le Pen might win in France

She might, but right now is very unlikely, much more than a Trump victory or Brexit. The problem is that she is losing in the polls by... a lot. For the French presidential election, all polls predict Fillon v. Le Pen. The only two polls conducted since Fillon was chosen candidate give him +34 and +42 (https://en.wikipedia.org/wiki/Opinion_polling_for_the_French...). 42 points was the distance between President-elect Trump and Johnson, the Libertarian candidate, in the last election.

I'm not saying it's impossible. Just very unlikely. The errors in the polling for the US Presidential Election and the Brexit referendum were much smaller.

And even if Le Pen is elected in France, the election for the parliament the following month would surely go in the opposite direction, meaning her power would be limited (since, in France, the government is chosen from the party with the majority in the parliament).

Still, I don't think that Le Pen would be that bad, especially considering the failures of the two last présidents.

That does not matter much in Germany, where the political system is very different from the UK and the US. Germany has proportional representation, which does not produce the two party system of the US.

The conservative parties CDU/CSU are totally sane compared to large parts of the UK tories or the republicans in the US.