cross posting this to reply over here:
In a correction to earlier speculation, I referenced Chinese naval “bunkers“ as potentially responsive to Trump’s announcement of AGM-183 specifications. I is now clear to me that the construction located on the coast of Hainan Island is specifically designed primarily to conceal, not protect, the movements of their intercontinental ballistic missile submarine fleet.
Additionally, the structure is complete, enormous, and in use. Therefore it could not possibly be connected to anything Trump said during his presidency.
Having said that; speed is not the only advantage of hyper-sonic missiles possessing terminal maneuverability. These cannot be defended against with current technology, nor do they need a “payload” to destroy a target. At mach 17, kinetic force alone is adequate to sink a ship. Trump also mentioned that the accuracy is measured in inches, not feet. I do not know if that is credible, but if it is, the Chinese have a real, and unsolvable problem.
I'm going to have to do some more research on that last one, will be interesting to see what rabbit holes that leads down. Kinetic energy certainly has it's own role to play in things the concept of "rods from god" in the form of mass driver attacks from orbit is now decades old at the point, and Mach 17 is a very different thing in regards to kinetic energy than the mach 10 China currently claims for their stuff.
I'd probably still hazard a guess that even a Mach 17 kinetic hit may not be up to
sinking a fleet carrier, but I don't doubt its ability to "mission kill" all the same.
Okay, some additional research just before hitting post:
kinetic energy (joules) = 1/2 x mass (kg) x velocity^2 (m/s)
Mach 17 is 5831 m/s, compared to 3430 m/s for Mach 10.
1 gram of TNT releases about 4184 joules of energy upon detonation.
5831 raised by the power of 2 is 34,000,561 but to make it like with like we'll reduce it to 1 gram of material delivered at mach 17. So 1/2 * 0.001 = 0.0005 * 34,000,561 = 17,000.2805 joules of energy released per gram that hits a target at mach 17, or equivalent to just over 4 grams of TNT.
H6 explosive, which is used in the MOAB, is 1.35 times more energetic than TNT. Of course there are other confounding variables to add into the mix(like simply "punching through" your target), but I'll have to agree that just looking at that, a Mach 17 kinetic strike weapon is nothing you'd want to be near where it hits if it has any mass behind it.
3430 m/s(mach 10) raised to the power of 2 gives 11,764,900 which works down to 5,882.45 joules per gram assuming it hits at Mach 10. H6 explosives release 5648.4 joules per gram by comparison, so from a raw utility perspective, it does look like somewhere around Mach 10 is where you hit the point that ditching the high explosives in favor of simple mass becomes a viable option.
An additional check finds wiki talking about the Naval Railguns firing at around Mach 7.