technology possessed by the military in this regard is incomprehensible. Countermeasures to prevent enemies from being able to track or chase the US nuclear sub fleet is one of the biggest issues for the military. Countries know the few places where these things port and can try to build virtually undetectable tiny ships that can follow them and then only chirp back if something gets hot (once they transmit a signal their presence becomes immediately known which is why being able to operate autonomously unless called is so critical). If a ship is ever sunk by a torpedo again it will almost certainly come from a UAV that is basically a torpedo transporter and not from a traditional ship. I don't know if the Virginia Class submarines could last a month in a hot war with China, who can manufacture UAVs in breathtaking numbers.

The USN has been working on this stuff for decades because they have so much territory to cover and the consequences of falling behind are so significant.