However, when it comes to all the other tasks that submarines take on, you should have no concern about their capability.
The other point I'd make about submarines is simply that it's important to recognize the contribution made to, let's call it the NATO navy, or on the west coast, to the allied navies. If you think of the RIMPAC exercises that unfold every two years off Hawaii, they are a great training opportunity, bringing the like-minded western nations together to practise their skills, and not only practise their skills but also make sure that what they're doing is known to the Chinese and the Russians by inviting the Chinese and the Russians either as observers or indeed, as happened last summer, sending a Chinese warship to participate in those parts of the exercises that were at an appropriate classification level. Why? Because it all contributes to deterrence when they get to come and have a close look at what our forces are capable of doing.
When you think of western navies, I'd like you to think as a practical example that China has 60 submarines, which it does; Russia has 40; and America has about 75. Remember that America's submarines are used globally every day, are demanded by each of the combatant commanders for all the things that they are able to do, including intelligence, surveillance, and special operations; and China and Russia have an advantage, which is that they can concentrate where they wish to be rather than worry about where platforms are around the world.