Article 4 in the 1902 treaty has no American exception

Did Article 4 exempt the United States because Britain had a separate arbitration agreement with America?

The answer reads Article 4 of the 1902 text as protecting the alliance from separate agreements. Britain remains neutral in a one-on-one U.S.-Japan war, while a coalition against Japan triggers support.

In the 1902 treaty being read, Article 4 bars separate agreements that prejudice the Anglo-Japanese alliance. The answer therefore rejects the proposed American exception based on an arbitration agreement. Britain would not automatically enter a war fought only between the United States and Japan. If another power joined the United States against Japan, the coalition trigger in this treaty would apply.