China is conducting vast undersea mapping and monitoring operation across the Pacific, Indian and Arctic oceans, what naval experts say would be crucial for waging submarine warfare against the U.S. and its allies. https://www.japantimes.co.jp/news/2026/03/24/asia-pacific/politics/china-ocean-submarine-warfare-us/?utm_medium=Social&utm_source=mastodon #asiapacific #politics #china #submarines #taiwan #us #defense