Every nation is capable of aggressive impulses, even modern Germany and Japan, with a suitable application of aggressive nationalism, which is different from normal nationalism. Japan channeled its nationalist spirit into commerce. The rest of Europe is so paranoid about Germany, post-Hitler, that anytime a nationalist pops his head up, he gets beat down(rhetorically).

One thing that could prevent any European nation from going back down this road is the dilution of the native populations. Unlike America, European nationalism is based on the way they percieve their connection to their land. It goes beyond the concept of race, and is almost a familial thing. With the influx of muslim immigrants, and the migration of European labor that the E.U. has facilitated, it's highly unlikely that we'll see anything like the Third Reich or British Empire ever again. Not because they "got it out of their system", but because the thing that makes traditional European nationalism possible has been broken.

Russia is a bit different. They have the same "blood and soil" thing as the rest of Europe, while they are also an ideological empire in the same way that America is, but the opposite, and their aggressive nationalist tendencies come and go in the same way.

Japan is only "commited to international peace and non-agression" because they aren't currently threatened by anyone but N. Korea, and it's good for business. I wouldn't be surprised if Japan and Australia are building up nuclear arsenals in the next 20 years(with American assistance) to form a regional counterweight to China and Indonesia.

I'll try to make this more coherent tomorrow, I'm stoned and tired.