It always had to do with weapons in space. They're mostly just ideas too. Clinton, though, was developing a ground-based system. They built various sorts of prototypes. A big issue is whether or not the system can deal with decoys.
Rationales change all the time.
It meant Iraq, Iran and Korea. But all of those countries have unique considerations. We kept trying to reassure them that our system wasn't aimed at them. But if it actually worked, it might suppress their deterrent force. Therefore, if you build anything bigger, it might definitely affect them.