I'm going to attempt to answer your question.

First, it's unlikely that this is a real project. War companies produce lots of random ideas for presentations hoping that one of them will catch on and get an initial program funded. A few years ago there were animations of a V22 mashed up with a C130 to get a tandem winged VTOL cargo plane. The warporn gets buyers in the mood, but what they actually buy are things like the F35 program and "palletized strike missions", which is a mid-air launch system for cruise missiles. Every cargo plane with an in-air openable ramp becomes a cruise-missile launching bomber.

Second, some prototype projects provide cover for other, more secret projects. If everyone knows that a lot of engineers are being hired for the SR-72 project, the fact that 25% of them are actually working on something else in the same facility is easy to disguise. Test flights of one hypersonic vehicle look pretty much the same as test flights of a different hypersonic vehicle.

Third, war companies provide a lot of skilled through professional level employment in the areas where they operate, and politicians find it acceptable to run employment programs that way.

Bc there's some treaty prohibiting space-based weapons smth smth... hence your satelite will not be able to carry missiles (or use them without admitting it carried them).

...and bc ICBMs are not weapons you'd want to EVER see used :)

You'd probably use this to hit a bad guy's house/hospital/school inside airspace protected by another superpower (hence drones and other stuff won't work) based on ground based humint whose information will likely be stale after a couple hours. It could mean way less victims than conventional warfare, so ugly as it is, it's better than destroyed cities and waves of refugees.

All in all cool to see superpowers doing dick measuring contests with these kinds of stuff, compared to other horrible stuff they could be competing at militarily...

ICBMs are a large, blunt weapon. Their value is primarily in their deterrence. The concequences of actually using them are so unthinkable, that we don't really consider it unless it's a very-last-resort kind of situation. Most of the time you want a precision, guided munition that can destroy a house or a truck or something small without causing too much collateral damage. Until now, that has meant an airbase or a carrier nearby to launch aircraft to carry these munitions.

However, with the XR-72, we can do away with those and just launch our precision strikes from the US mainland. It's cheaper, just as effective and hopefully will give emerging superpowers (like China) pause when planning their defence scenarios.

Hypersonics is like fusion, everyone needs to be doing it. They’ve been trying for decades and so far it’s been a bust.

Queue news stories about Chinese or Russian hypersonics with zero real data and calls by the MIC to close the “hypersonic gap”

In the pantheon of weapon systems it is simply the most expensive way to do something.

ICBM go up and down in a predictable arc. Sometimes they have the capability to shift their path actively but not by much. Hypersonic controlled flight vehicles have the ability to be unpredictable and therefore offer more protection from countermeasures.

Well we need to feed the beast because we love freedom and if you don;t you are free to go to gulag... or something along those lines.

> Given satellite technology and ICBMs

I see an SR-72 being a hedge against losing both of the above, or having them rendered ineffective.

Putting a nuclear munition on this thing makes sense to kind of get ICBM like capability in a ditch, and ensures you have something against the enemy who can reliably intercept ICBMs.

Same for the case spy sats get taken down. The chance of the enemy having something that can intercept high speed aerodynamic targets, as well as satellites at the same time is minimal.