The Road To Pearl Harbor, 1919-1941 Season 1 Episode 15 Japan Invades China: Crisis in the Far East:

In 1937 Japan was bent on establishing an empire. Encouraged by the lack of Western resistance, Japan took control of French Indochina, the Dutch Indies, Burma, Malaya, and the Philippines. By mid-1941, Roosevelt had enforced a total embargo, freezing all assets originating in Japan. In the face of this economic pressure, the Japanese government decided to force the United States into war.