The paper describes Japan as an American protectorate, which means that the United States, specifically the United States Forces in Japan (USFJ), has violated Japan’s sovereignty since 1952 when Japan regained her independence. It reviews different opinions on Japan’s status toward the United States and considers the external threats against Japan, which the United States Government and the Japanese Government emphasize. Both governments argue that Japan needs the United States Marine Corps in Okinawa as deterrent. However, nobody clearly states whom deterrent should be aimed at. Who is a potential enemy? Neither the United States Government nor the Japanese Government specifies their enemy. Therefore, this paper examines potential external threats for Japan. The paper concludes that Japan should rely on diplomacy rather than her military forces.