The South China Sea remains the most contested region in the world. If recent signals from the Obama administration are credible, it’s about to become more contested as the U.S. challenges China’s island-building campaign in the international waters of the South China Sea.
Many nations dispute claims over groups of islands, reefs, atolls, seabed mineral rights, and large swaths of the South China Sea that are important for economic, navigational, and security reasons. The disputes continue to increase tension in the region. Vietnam has purchased Kilo submarines; Malaysia is upgrading its coastal navy; the Philippines are weaponizing their AW109helicopters; and Japan continues its naval buildup.
In the meantime, China continues to grow its stockpile of missiles across the Taiwan Strait and refuses to disavow force as a means of settling its dispute with Taiwan. Faced with the possibility of a future blockade or amphibious attack, and unaided by its friends in a decades-long effort to build a defensive submarine force Taiwan has chosen to upgrade its naval capabilities by building its own submarines.
Source : https://nationalinterest.org/blog/the-buzz/the-master-plan-upgrade-taiwans-military-new-submarines-14327