After the Vietnam War, the US Department of Defence considered withdrawing the Marine Corps from Okinawa to the mainland US. However, the Japanese government, unable to stand alone in terms of defence policy, intervened to stop it. Observing this, the US State Department thought that it could use the Marine Corps as a lever in its policy towards Japan.
These historical facts become clear from documents in the Australian Archives discovered by Nozoe Fumiaki, lecturer at Okinawa International University. Preserved in the Australian Archives are reports from Australian diplomats on what they had heard from State Department officials.