Duh! Have you ever considered "nuclear blackmail"? If Iran can send nuclear missiles on defenseless European capitals they can blackmail the Europeans to fulfill each and every wish and whim of the Mullahs. It's not about actually thwarting the unlikely case of an Iranian nuke attack. It's about avoiding a situation in which Iran can blackmail Europe. And we know that MAD doesn't work with Islamic lunatics. We need to demonstrate them the futility of an attempted blackmail/attempt. That's only possible with Missile Defense.
That idea totally makes sense. If that’s the case then why not set up the systems in Italy or Greece. They’re much further south, and in better position to tackle incomming missles?
The fact that the systems are to be positioned way up north and East towards Russia is pretty telling. It’s like having a neighbor with a machine gun pointed at your house.