US Navy Dieselsubs

How serious is the idea of the USN to acquire a certain number of dieselsubs ? Now the giant threat of the Sovietfleet is gone there is no other country in this world wich has a bluewater navy capable of endangering the mighty USN in the open sea.

With future conflicts in mind some people think there is again need for dieselsubs in US service. A possible scenario being a conflict with China were (Japanbased) US SSKs can do a great job in the shallow waters of the Chinese Sea.

How serious are those plans ? Will the US take the effort to develop its own subs or will it buy them off-the-shelf from countries like Germany and Sweden (kockums), the Aussies as an example with their Collins-SSKs

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