Taiwan has carried out the maiden torpedo test-firing from its first domestically developed submarine, a major milestone in a project aimed at strengthening deterrence against the Chinese navy and protecting vital sea lanes in the event of war.Taiwan, which China claims as its own territory, has made the indigenous submarine program ‌a ‌key part of an ambitious project to modernize its armed forces as Beijing stages almost daily military exercises to assert its sovereignty claims.The submarine program has drawn on expertise and technology from several countries, including the United States and the U.K., a breakthrough for diplomatically isolated Taiwan, whose government rejects Beijing's territorial claims.