Meanwhile we have pretty much nothing to defend against ICBMs because increasing spending on defence wasn't seen as a good way to spend money...
Unless its been tested in real conditions you cannot believe any capability to be proven. Its like I can demonstrate my ability to hover in the air, however the fact it was a video in slow motion and all I did was jump proves nothing. Likewise the agile / hypersonic missiles that have been in the news, how many attempts were unsuccesful before they issued one successful one?