Being duped into hating your fellow in the proletariat and seeing killing them to "protect your nation" is very easy to do in times of war, and people there, from the communists-in-hiding to the Nazi bozos Sieg-heiling on the frontlines get to experience the horrors of war.

Many can't deal with it and go abroad to a safer haven.

Here, you have not just thousands - millions of Bozos for whom you are also merely an instrument for advancing that state's interests. Be it working at shit jobs for shit-euro-pay or getting sent back to die in a WW1-Style-trench. Who hate you if you are too much of a loser to fulfill their ever rising demands, who hate you if you dare existing too obviously.

The Europeans eagerly march into the same hatred as above, millions supporting the military, Sabre-rattling, even open warfare! All to show strength, even if it causes WW3!

Willing to FUCKING DIE for the nation, for its interests, economic and/or political, to own the evil barbarians (the same is highly likely to be said in Russia)

Proletarian Internationalism? But have you considered everyone but me us (and they say humans are selfish by nature) is morally evil!

And anger against all this doesn't seem to be going anywhere, just into people who are considered better managers of nationalism - the fash.