Setting aside for a moment the rather large conflict that ended in 1945 - if you're in your late 20s or older, both Libya and Kosovo happened within your lifetime and meet your criteria.
1 That was not an Article 5 thing,
2 how many USA soldiers gave their life in Kosovoa?
3 1945/ww2 I think USA was attacked by Japan, americans did not enter the world to protect Europe, they were forced in the war so they had no choice then to fight their enemies wherever they are.
The American strategy in WWII was "Germany First" despite it having been the Japanese that attacked us.
Anyway we talking about NATO, USA used Art5 and Europeans died for USA, but now Trumpists complain that we are not doing enough and USA will not return the favor
https://en.m.wikipedia.org/wiki/Declarations_of_war_during_W...
Based on a quick wiki scan looks like two. This accounts for all NATO casualties. No Romanians were killed in Kosovo.
A combined total of 30 Romanians were killed in Iraq and Afghanistan.
So far Europeans died in USA conflicts around the world , how many conflicts did Europe start and USA had to get involved so far ?
From me a Romanian, feels very shitty that our soldiers died in Iraq and Afghanistan for America but now if we will need help Trumpists will not help back.