I think I understand why the US and central european countries have so different reactions to foreign interventions/participating in conflicts outside of ones own borders than the US: the US didn't experience the two world wars the way european countries did.
this is more clear in the context of WWI: an austrian is shot in serbia, because serbia wants independence, but russia intervenes because it wants to control serbia, and germany & austria fight russia, and france has an alliance with russia, and germany always wanted to fight france anyway, ……… the level of intervention and trying to intervene in other countries' affairs leads to a chain reaction that brings about calamity.
on the other hand, the US comes in and there's already a conflict going on elsewhere, it's not quite clear why it's happening, but it looks like it's bad, so “we can go over there and shut up the bad guys” *star spangled banner blares*
(don't talk to me about muh pearl harbor, that's a blip compared to what happened in europe.)
so that's why i think (at least some) european countries are (at least somewhat) more hesitant to go out and intervene in the affairs of others
additionally, some countries (*cough cough*) had some, let's say, embarassing behavior in the world wars
none of the two worldwars took place on US soil, and the US entered both conflicts relatively late, so there is less US cultural knowledge about them (mostly in the form of “relative X went overseas and died/came back traumatized”). but in europe, the countries were the place the WWs were happening. and they experienced a different way how those conflicts came to play: countries interfering in the affairs of other countries.