I will respond since this was replied to me.
What is the operational support infrastructure in APAC region for these submarines if China understands what's coming & destroys supporting bases in the region?
What is the role of US submarines? Is it to just come in fire off the missiles and scoot back to base to reload. Keep in mind, you have to elevate to periscope depth in order to fire cruise missiles, so once you fire, your immediate position is exposed. You'd have to probably be within 800nm of China's coast lines, so it is very likely you are within flying distance of a Chinese MPA or ASW helicopter. Keep that in mind.
Or is your goal to prevent Chinese nuclear submarines from existing 1IC and getting into position.f
So the latter part is the critical one that I was pointed to with 09X. If your sub is quiet enough & USN during peace time does not have the asset to actually tail Chinese subs as they cross 1IC (where SOSUS and other trip wire are), they are then basically free to go wherever they want.
So as such, peace time sub ratio in APAC region is a big deal. Chinese subs dealing with 25 USN subs right next to them during peace time is entirely different than facing 6-8 (half of which are LA class).
Having enough 09X means you can have them using those big sensors to look for USN subs between 1st and 2nd island chain. You can have them go even further to close to where the USN subs are resting in docks in west coast and Hawaii. So that when they leave, your subs can tail them. These all make huge difference.
China never really had subs that are quiet enough to get into open ocean and keep up with American subs. It's possible that 093B is the first to potentially be able to do so.
But something like 09X would be quieter and can go quietly at very high speed to really tail US subs.
The US using submarines to launch land-attack missiles is really inefficient. Especially since they have other options from local bases.
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And with enough 09X, instead of them actively looking for US submarines, I think it's better to deploy them against potential targets, which forces US submarines to defend.
For example, the US typically has 2 carrier groups plus an LHD deployed.
If China assigns an SSN to each of these noisy, visible targets, the US will likely deploy an SSN to defend.
Then China could assign a submarine (SSN/SSGN?) to San Diego, Seattle and Hawaii. So the US would likely deploy SSNs to counter.
That would tie up 6 submarines each from the Chinese Navy and US Navy.
Note this completely ties up the 6 US SSNs (out of 50) which are typically deployed at any time.
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From the Chinese perspective, the Chinese Navy would likely want SSNs to escort its own carriers and LHDs, along with a few for the Indian Ocean and also Westpac generally.
So that is already 10+ deployed Chinese submarines at any time, which implies a fleet of 80+ nuclear-powered submarines.
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Whilst the US typically has 6 US SSNs deployed at any time, they could surge 20+ with very short notice
It means that if there is a deployment surge by the US submarines, the lone Chinese submarines outside the bases will be overwhelmed by the number of outgoing US submarines who will disappear into the open ocean.
In response, I think we would see some of the Chinese SSNs form a screen (somewhere between the 1IC and 2IC) because we know what is the final destination of the US submarines.
The screen can also be supported by MPA/fighters from land-bases and aircraft carriers, and this is a far enough distance to manage submarine launched missiles.