In the meantime, dealings with Japan persistently to worsened. In September 1940 Japan persuaded Vichy France into conceding northern Indochina. In an effort to resolve the situation, the U.S. sought after halting Japanese expansionism, although the isolationist population still remained substantially large therefore preventing action without Japanese aggression and provocation.
The U.S. proceeded by prohibiting the exportation of steel, scrap iron, and aviation gasoline to Japan. Further, in July, the United States froze Japanese assets to avert Japanese acquisition of oil, a critical resource during wartime.
Moreover, the advocates of war were feared that it was not adequately prepared for a war with Japan, after the signing of the Tripartite Pact in 1940, which provide an allied defense between Germany, Japan and Italy therefore confirming a two front war for the United States.
In due time, the strategic diplomatic maneuvering of the Roosevelt administration came to convince Americans that the security of the United States was dependant on the defeat of the Axis. Interventionism, support by only a slim margin of Americans prior to 1939, flared up. …
