The US hasn’t had a domestic war since the civil war. How many wars has Europe had domestically since then? Hmmm.
The US is a country, Europe is not, so “domestic” is a misnomer and the comparison doesn’t hold up. The issues Europe had with wars are a result of complex regional and historical issues, those things don’t really exist in the US because it is too homogenous on one side and too much of a military might to challenge on the other, not to mention geographically isolated.
You really need to reach to make Europe look like the bad guy when it comes to wars, not in the least because the US takes other countries to war all the time to throw it’s weight around and establish dominance.