Pay 2% of GDP on Defense first.
Also if the EU wants to stand up to the US and they refuse to pay their 2% fee the US should make sure their are some consequences for this .
What fee are you talking about? Good Lord, there is no "NATO FEE", it simply does not exist.
Each country pays into its own defence budget, and the 2% is a "NATO recommendation", not a fee.
The EU military budget is around $230 Billion, so yeah, I think it is enough, considering that it is on par with China (a country with 3x the population), and 4 times the amount Russia invests.
So yeah, unlike what you think, no one is invading Europe if you pull out, seeing as it is the 2nd/3rd biggest spender after the US.