[Little Ray]

Because they are, essentially, defensive weapons. You can’t send ‘em across the ocean to patrol and destroy the enemies’ naval forces and merchant marine (can we attack merchant ships any more?). Also, they can't keep up with fleet.

You are right. We should have some similar subs for our own forces to train against and service in one should be as prestigious as being in one of the aggressor squadrons for "Top Gun" training.

[rahbert]

We lease the Swedish subs for ASW practice. Far cheaper
than owning. Plus the Swedes get to visit Kaliph.

[El Gato]

Because they are, essentially, defensive weapons. ou can’t send ‘em across the ocean to patrol and destroy the enemies’ naval forces and merchant marine (can we attack merchant ships any more?).

We have shores to defend too. And some "short" sea lanes as well, to the Caribbean and South America. And as you point out, we need them to train against, because many of our potential adversaries have small quiet subs.

I'm not sure that the AIP subs have quite the same limitations as conventional Diesel electrics. They can stay down a long time. Maybe not as long as a nuke, but they are smaller, which can be a stealth feature, and could be as quiet.