ORIGINAL: NakedWeasel
Which is to say to us skeptics, "Maybe it works, and maybe it doesn't, so be afraid just in case." That's fine. I'll prepare my fleet and personnel to defend against a very unlikely or non-existent threat, anyway. The US and her allies are already much farther along in their defensive measures against the ASBM than the PLAN's ability to use them as a deterrent against a CTF/ESG. The Chinese are banking on a "maybe threat". The US will continue to develop weapons like free-electron lasers and hit-to-kill vehicles that will be PROVEN to function before they are ever put to sea.
That's fine by me, but maybe you are underestimating your adversary quite a bit.
For all we know from the leaks and official news coming from China in the last couple of years; the PLA also works on the exact same things, including fre-electron lasers, KKVs and quantum radars (with already a working prototype tested last week).
Every China/PLA watcher worth his salt knows that China is very secretive with even the most basic information of their military development. While it is part of the US' deterrence strategy to openly boast about their new next generation weapon developments, even before a prototype has been built, China doesnt even release official data on their obsolete systems, let alone any currently deployed systems.
For all we know, the now-revealed four test of the DF-21D's between 2014 and 2015, could have been the moving sea-target tests that would qualify this weapon as being "proven" by any normal measures. Other PLA watchers have noted certain NOTAM and No Navigation Zones declared in the Gulf of Bohai during this period, which could indicate ASBM testing against sea-targets.
Of course, if you want to move the goalpost and only consider a system "working" if it has proven itself in a real war, then many of the USN's current systems should also lose their status of being "proven" and "working" - last, but not least, the Aegis Combat System, which has never demonstrated in a real war its famed capability to defend against the sort of supersonic multi-dimensional saturational attacks that it was originally designed against.
So, let's better stop this, as this discussion can quickly become quite nasty and nationalistic.