Long-range, highly-capable submarines are a wild card in naval warfare. For one, they can threaten shipping and other nations. For another, they can neutralize or at least threaten aircraft carriers.
So, what are the intentions of Russia and China? Even if we thought we knew, the capability projects threats decades out when they may change their minds and we may find ourselves unable or unwilling to defend against it.
The Moscow Times reports that next year Putin will spend twenty five percent more on defense–all marked for weapons systems. Despite closing hospitals and slashing health care, Russia still spends more on defense that the United States (per GDP). (Of course, some of this is graft for his cronies, but none of it is “improving the notoriously atrocious conditions for conscripts.”)
Both countries are well known for being at the forefront of cyber hacking.
Military research and development is risky and expensive. Not keeping our technological edge is even more so.