Japan would really be thumbing their nose at mainland China if Taiwan got Soryu class subs:
Taiwan Turning the Screws on Washington’s Sub Deal
By Wendell Minnick 4:42 p.m. EST December 5, 2015
Yang admitted that Taiwan was “in communication” with Japan for a possible deal for Soryu-class submarines. Japan’s export defense restrictions have been eased, and Japan and Australia are currently working on a joint submarine program.
Bob Nugent of AMI International, a Bremerton, Washington–based naval market analysis and advisory firm, said he could “envision a scenario where there is an outright sale to Taiwan of Japanese submarines.” The current price is around $500 million a hull for the Soryu, and that includes airindependent propulsion — significantly less than the US offer estimated at $800 million for just the design stage.
China and Japan are bickering over control of the Senkaku Islands in the East China Sea, which Japan controls and China claims as its territory. Additional friction was created in 2013 when China announced an air defense identification zone in the East China Sea, which included the airspace over the Senkakus. Increased Chinese fighter and surveillance flights into Japanese air space in recent years have also rattled Tokyo.