This is a really good 7 minute video from the Rand Corporation on hypersonic missiles. There is currently no defense against these things. I really liked the hypersonic glider that hits its target with enough kinetic energy that no explosive warhead is required. I bet the cost engineers were really impressed with that.
Hypersonic Missile Nonproliferation
https://youtu.be/FyUTNRIuAqc
intercst