We use same kind of Russian subs, the kind Vietnam is buying, as anti-sub training for a long time. We even develop our new subs from their strength while getting rid of their weaknesses.
Our subs have roamed western Pacific and our own South China Seas for decades. I'm sure we have as much advantage, or even more so than Vietnam
Our subs have roamed western Pacific and our own South China Seas for decades. I'm sure we have as much advantage, or even more so than Vietnam