That's got nothing to do with Romania joining the EU They'd let the US do it anyway because they don't want the Russians back
You can`t really have them piss off the Russians by pointing US missiles at them, but not let them be included in Europe.
Doesn't really matter as Russia have a ballistic missile that makes a mockery of any other current ballistic missile in the world and any missile defense system trying to shoot it down.
US Military bases vs Aggressive Iran. please log in to view this image To be fair I'd rather they were US bases than Iranian.