Which agreement are you referring to? The commonly cited 2% agreement that I'm aware of was for 2025 - which all members reached. When was Europe ever non-compliant?
Of course they have renegotiated, and so now the target is 2% by 2027, with all historical arrears forgiven, and several countries have already publicly announced they agreed to it, won't do it (Ireland and Spain I'm aware of, I doubt they're the only ones)
You could also see this as most countries joining, promising to do this starting in 1949. Not even in the first years did most countries do this (except France). So most countries are let's generously say 1% of GDP in arrears, for 75 years now ...
Could you please share where the 2% were defined in the requirements since 1949, and where the 4% are currently defined?
As I already stated, the 2% requirement I'm aware of was negotiated in 2014, to be reached by the end of 2024. If this is indeed where the 2% come from, it's obviously completely ridiculous to act like the member countries didn't meet the requirements - it wasn't a requirement of the treaty they signed!
If the US wanted the 2% target to be met before then, you should have negotiated an earlier deadline. Don't agree to one deadline and then cry because an arbitrary earlier one hasn't been met.