We saved Europe and that helped preserve our own security but that wasn’t the only reason America fought the World Wars. Now, Europe itself threatens America’s security. Maybe it finally is time to pull out of Europe. Let them fend for themselves. If they can’t save themselves, what use are they to anyone?
The EU is of great use.
To our nation’s enemies.
I'd question to what extent WW1 preserved our security. I think it might have been better had they been left to settle their own quarrels. Though I acknowledge that might have provided an opening to Marxists beyond Russia. But that wasn't an issue at the time.