Mach 20? Not yet. The Russian missile has a stated speed of half that. Russians have a long history of overstating the capabilities of their weapon systems. See Mig 25 foxbat.
The US has tested designs with that potential speed but no production system is known to exist.
Futurology
Both the US & Russia have claimed Mach 20 with the HTV-2 (DARPA's Falcon Project) & Avangard respectively. China’s DF-ZF HGV reportedly reaches Mach 5–10.
If this golden dome goes ahead, I suspect/guess the ensuing counter-developments will mean true Mach 20 will be achievable within a ten year time frame for all three countries.
Yeah, They claim it for test bed projects. Not a production weapon systems. Just like I said the first time. As for the Chinese, Mach 5-10 is less than Mach 20, yes? You said Mach 20. I said not yet and its still not yet. Ukraine has shot down putins hypersonic peckers with upgraded patriot systems which date back to 1981. The new systems will work better. I bet the russian missile probably doesn't hit mach 5. The russians always lie about capabilities of their weapons to the extreme.
I did quite a bit a reading about it when russia was launching their "un killable" missiles a few years ago. Just like I read about the Mig-25 and how its capabilities decades ago. The claims there were vapor. I still have a book from the 80's that had a huge amount of information about all of the in production fighters from then. You see the problem they have today is the problem they had in the 70's when hypersonic test vehicles were first flown. The friction and forces involved in travel at those speeds cause the atmosphere act more like liquid water than a gas. They achieved those high speed at 100,000 feet altitudes to mitigate that heat buildup. Even modern materials can't take that amount of friction and the heat buildup for long at near sea level. The area of the atmosphere where a hypersonic missile would operate.
Finally you need to understand Mach 20 is close to orbital speed. At sea level the range where Mach speeds are calculated from is 15,534MPH or 23,854 km/h.
A minimum orbital speed is around 17,000MPH or 28,000 km/h. It is unlikely you will ever have a mass produced weapons system that can maintain that speed in the lower atmosphere unless they come up with some remarkable materials that can take that amount of friction and heat buildup without failure.
So we are back to Mach 20? Not yet.
Here read this
There’s no such thing as a “safe” nuclear war. If enough nukes go flying, it’s nuclear winter for the whole damn planet.
Torpedos, ship launched short range, and truck bombs, from border countries made hostile, or at least indifferent to usa destruction, is one counter measure. As article mentions, overloading a target location with decoys and faster missiles is another.
Usa risks collapse simply from trade war disinvestment. A single nuclear strike or even just a hurricane at this point, will pass tipping point.
$175b is optimistically low. Previous quote was $2.5t. just last month. Like all boondoggles, proper marketing is for initial bribes, which are $25b, in this year budget, for under budgeted scam with overages to vendors. $25b is campaign donations and media brines.