I don't believe that Japan will act in isolation, but I think that if the United States is engaged in a conflict, then Japan, likely Australia and potentially even the Phillippines, as a treaty ally, would play a role. What type of role I think would take a much longer discussion, and I think that's not public, but I think they would play some sort of role in such a contingency.
On November 15th, 2022. See this statement in context.