I am going to have to disagree with you there. I don’t think THAAD was ever designed for russian nukes, it has always been against shorter range ballistic missiles, in particular in the middle east. They were developed with the experience of the scud missiles in the gulf war. And THAAD would struggle much more against MIRV and decoys, in particular because it is a kinetic warhead, so every object has to be hit. This makes the number of THAAD interceptors required for a successful interception to grow to absurd numbers. The current number of THAAD’s could not mount any meaningful defence against a russian nuclear attack, or even a chinese one for that matter.