Earlier quoted context omitted.
Russia already has hypersonic. And there is no realistic defense against them. They scare the crap out of DC because a Russian sub could pop up off the coast of New Jersey and 5 million people including 99% of all US politicians would be dead 6 minutes later. So of course the US needs them.
20 minutes later Russia would be dead. 20 minutes later the world. Been like this for many decades. That it hasn’t happened is kind of surprising.
They would have to retaliate on every other (non-allied) country.