Many in the USN submarine ("USNsub") service are arguing that a high spec (hence high US$5-6 Billion cost) Future Attack Submarine aka "SSN(X)" is required from the early 2040s to have the edge over improving Chinese and Russian SSNs/SSGNs.
USNsub desire a large "Seawolf 2" solution carrying about 50 heavyweight shots ie. a larger proportion of torpedoes and anti-ship missiles and lower proportion of Virginia class favoured land attack Tomahawks. Hypersonic anti-ship and hypersonic land attack missiles would also feature.
A 15 year debate is likely - similar to the earlier Seawolf-class (29 envisaged, only 3 built) Debate. Those opposing the USNsub lobby are likely to be the USN surface force lobby, whole of Navy lobby, other armed services, Pentagon bureaucracy and Congress. They may push for a continuation of Virginia-class construction through to the 2050s or a lower spec class than a "Seawolf 2".
Programs competing with the SSN(X) include:
- 12 Columbia-class SSBNs
- 20+ new Constalletion-class frigates
- 20+? 10,000 ton cruiser sized Future/Large Surface Combatant aka DDG(X) Program
- Many different types of land, sea and air launched Hypersonic Missiles.
- and many other weapon, personnel and new base building programs.
It is inevitable that the SSN(X) program will be more expensive than the Columbia-class. With 2 main near-peer competitors, Russia and China (the latter having a huge economy), the US will need to intensively debate and economize on its submarine choices.
Here and below is a useful 5 minute, May 27, 2021, video on the SSN(X) which seems to be according to USNsub lobby aspirations. For example, from 34 seconds in the Video claims the USN is planning SSN(X) deployment "beginning in 2031". That is more than 10 years before other lobbies and factions estimate the first SSN(X) will deploy (in the early 2040s).