A LITTLE BRIEF PRIMER ON THE THAAD:
The THAAD system is designed to intercept medium to intermediate sized missiles, and even has some capability against Intercontinental Ballistic Missiles (ICBMs).
Using advanced radar, the THAAD system launches a missile that intercepts the incoming threat. The THAAD missile has no warhead, and is only designed to strike and detonate the incoming missile’s warhead while it remains at a safe distance.
The U.S. sells all kinds of tech to all kinds of countries.
But UAE is the first country other than Israel to get THAAD.
THAAD uses a kinetic kill vehicle. It only has to barely glance it a supersonic closing velocities. It doesn't matter what state the enemy warhead is in after that instant of contact, within milliseconds it's going to be spinning and shredding itself into thousands of melty pieces.