Put yourself in their shoes, wouldn’t YOU train to sink an enemies capital ship in times of war?
We sure as hell do, why would it surprise anyone that others are doing the same to us.
Our subs are probably tracking and plotting course on every sub we know about of theirs, this is nothing new at all and should be expected.
They should be afraid of our nuclear attack subs. Very afraid. The only caveat is that the Chicoms have their boy in power here now.