Operation Setting Sun was the name given to the theoretical and planned Allied invasion of Japan, set to have occurred either in late 1929 or early 1930 using American, Siberian, Colombian and Oceanian soldiers to end the Pacific War. The plan was regarded as one of the most ambitious operations in military history, and used Japan's own attempted suppressant invasion of the United States in 1925 as its model. However, the operation was still only in the early planning phases when the Hilo Accords were signed, thus ending the planning process.