Actually the missile defenses Bush planned in Poland and Czech Republic would’ve protected the East Coast of the US from Iranian ICBMs. Out East Coast has absolutely no missile defenses now.
Russia objected to those missile defenses on the pretense they were targeting them, but they know darn well that no missile defenses will protect the West from their arsenal.
So now we want to spend billions and billions trying to piss off Putin by building a missile defense system that doesn't threaten his ability to nuke us to begin with? And which is supposed to defend us agains Iranian missiles that don't exist? That doesn't make a lot of sense.