Nine Allied powers had representatives sign Japan’s Instrument of Surrender after Douglas MacArthur.
The signatories represented the United States, China, the United Kingdom, the Soviet Union, Australia, Canada, France, the Netherlands, and New Zealand. Fleet Admiral Chester Nimitz signed for the United States after MacArthur had signed as Supreme Commander for the Allied Powers.
The ceremony’s order reflected the coalition that had fought Japan across the Pacific and Asia. Some Allied governments sent senior military representatives, while others were represented by generals, admirals, or air officers.
The number nine refers to the Allied powers represented by their own signatories after MacArthur. It does not count Japan’s two initial signers, Mamoru Shigemitsu and Yoshijiro Umezu, and it does not mean that only nine nations had participated in the wider war.