Why Japan’s hypersonic and underwater weapon plans might worry China

In its latest swipe at Tokyo’s military build-up, China singled out Japan’s plans to arm its submarine drones with long-range missiles and test hypersonic weapons in Australia.

Analysts say those moves could threaten People’s Liberation Army amphibious groups and surface combatants within the “first island chain” – potentially affecting the PLA Navy’s ability to operate in the event of a Taiwan conflict.

The strategically important first island chain stretches from Japan to Taiwan, the Philippines and Borneo.

China’s defence ministry spokesman Zhang Xiaogang highlighted the two initiatives on Thursday, saying Japan had “openly expanded its military arsenal”.

Zhang said the “dangerous” moves had a “striking resemblance” to Japan’s pre-World War II militarisation, though he did not explain why these particular weapon programmes could pose challenges for the PLA.

Japan has rapidly expanded its long-range strike capabilities since adopting a “counterstrike capability” in its 2022 security strategy. Under the policy, Tokyo says it could strike military targets in an adversary’s territory for self-defence following an armed attack, while pre-emptive strikes remain prohibited.