Pronanly to use against us....
Eons ago I was listening to either Long John Nebel or Barry Farber. There was the usual discussion about all things UFO.At the end of the night one guest asked another, a Brit sci fi author, what nation or agency would likely be investigating this type of tech. He answered immediately “ the United States Navy”. The Navy he opined had a long history in investigating and developing advanced tech even if they had not publicized their results. So if there are to be hypersonic weapons I would not be surprised if the Navy not only had them, but had a means of defending against them.