ChiPing.
The Cowpens is one of our most powerful surface combatants and air-defense cruisers.
My guss is, that as the Chinese carrier and its four escorts came down from their home port and transited through the Straits of Fromosa (where they took care to remain on their side of the line), the entetred the South China Sea and the US sent the Copens to shadow her.
Why the Cowpens? She is usally part of a US CSG of which there were two in the vicinity at the time (at least a couple of hundred miels off if not more), and she is not usually what you would call a surveillance ship...though she has plenty of sensors to act as one.
she was probably simply the nearest vessel at the time. I bet there was at least one US SSN nearby, and probably at leas one other surface vessel.
Anyhow, she may have ha dorders to see how close, in international waters, she could get to the Liaoning. The CHinese decided she had gotten close enough and warned her off. The Copens CO decided he could get closer.
There is no way that lumbering Type 72 LST got in front of her and "stopped." Takes far too long for that, and long before she came to a dead stop the Cowpens could easily manuever out of the way. My guess (again) was that the LST manuevered from some time in advance, to block the Cowpens from gettting closer to their carrier.
It is true that that LST has a couple of twin 37mm gun monuts. And at close range, those weapons could hurt the Cowpens. But the Cowpens has two 127mm naval gun monuts, two 25mmm gun mounts, and two 20mm Phlanx mounts, not to mention 4-5 .50 cal mounts. Along with eight Harpoon Missiles. There was not a danger of gun play IMHO.
These are the types of games that are played between large sea powers that have conflicting interests.
I do nt see anything highly irregular here...except that instead of one of our smaller, less well armed surveillance ships, we sent a cruiser to do the job.
Just my two cents.