NHK reported a trilateral exercise involving the helicopter carrier (soon-to-be fixed wing aircraft carrier) Izumo and ships from the Royal Navy and US Navies.
Japan’s Maritime Self-Defense Force is to conduct its first joint drill with the US and British navies in the Pacific off southern Japan later this week. The MSDF says its largest destroyer, the Izumo, the British Navy’s HMS Argyll, and a US naval vessel will take part in the exercise. In the drill planned for Saturday, personnel will check the roles for each vessel and the procedures for information-sharing based on various scenarios, including conflict situations. The exercise is apparently aimed at showing the partnership among the three countries amid China’s increasing maritime activity. The mid-term defense program, approved by the Cabinet on Tuesday, says Japan will actively promote bilateral and multilateral drills. The SDF will be given more opportunities to strengthen its partnerships with the forces of other countries.
A follow-up report is here on Def Post.
Another here in Stars and Stripes.
This gives form to the trilateral naval agreement signed in October 2016 at the Pentagon by the chiefs of all three navies, committing them to “strengthen maritime contributions for achieving mutually desired strategic effects”.
It is not quite the post-World War I “Four Powers Treaty” Britain, France, Japan and USA signed in 1923 in the wake of the Anglo-Japan Alliance (1902-1923), but it is getting there.