In the past, US military planners have treated Japan as a forward position for its troops in East Asia, but without much coordination with historically underdeveloped Japanese forces, and this move underscores the deeper investment Japan has made in recent years in its own military capabilities.
It’s also a response to a perceived growing threat from China, including in the Taiwan Strait. (The Kishida administration has referred to Taiwan as Japan’s “extremely crucial partner and an important friend.”)
It signals a stronger stance by the US and its East Asian allies on threats from North Korea. And thanks to the improvements in Japan’s relationship with South Korea, Seoul is not objecting to the upgraded ties as it once might have..
The specifics will take months for senior US and Japanese officials to hash out, but even the initial announcement will raise heart rates in Beijing.