Above your pay grade, and mine too.
Let me speculate, we don't have an unlimited number of THAAD systems.
We are provoking a trans arctic ballistic missile attack.
If you were in charge would you deploy THAADs to defend Kiev or Washington DC (where you live)?
If I were in charge I would never have told Ukraine to ignore the Minsk agreements and there would be no reason to deploy THAAD missiles to Ukraine.
We started the war, and continue to conduct it. It appears to me that the Deep State and Soros want Russia to launch a successful nuclear attack on Ukraine so they can have plausible deniability for the inevitable nuclear world war that will follow.