I think you may be forgetting the big picture, which is to never have Europe spawning a World War again. In that regard, the fears (rational and irrational) of those with tendencies for isolationism are simply not relevant.
what are those odds looking like in the mid future? How many european governments are currently considered on the "extreme" spectrum?
And what makes you think the Euro implemented in 2002 is the reason for the non-reoccurence of a war ended in 1945?
Studying the root causes of the two world war would certainly enlighten
