Four days after the attack launched by the Japanese on the United States fleet in Pearl Harbour on December 7, 1941, Germany declared war on the United States.
The Tripartite Pact between Germany, Italy, and Japan, had been signed on the 27th September, 1940, and from that date until the attack upon the U.S.S.R., the defendant Ribbentrop, with other defendants, was endeavouring to induce Japan to attack British possessions in the Far East. This, it was thought, would hasten England's defeat, and also keep the United States out of the war.
The possibility of a direct attack on the United States was considered and discussed as a matter for the future. Major von Falkenstein, the Luftwaffe Liaison officer with the Operations Staff of the OKW, summarising military problems which needed discussion in Berlin in October of 1940, spoke of the possibility " of the prosecution of the war against America at a later date."
It is clear, too, that the German policy of keeping America out of the war, if possible, did not prevent Germany promising support to Japan even against the United States. On the 4th April, 1941, Hitler told Matsuoka, the Japanese Foreign Minister, in the presence of the defendant Ribbentrop. that Germany would " strike without delay " if a Japanese attack on Singapore should lead to war between Japan and the United States. The next day Ribbentrop himself urged Matsuoka to bring Japan into the war.
On the 28th November, 1941, ten days before the attack on Pearl Harbour, Ribbentrop encouraged Japan, through her Ambassador in Berlin, to attack Great Britain and the United States, and stated that should Japan become engaged in a war with the United States, Germany would join the war immediately. A few days later, Japanese representatives told Germany and Italy that Japan was preparing to attack the United States, and asked for their support. Germany and Italy agreed to do this, although in the Tripartite Pact, Italy and Germany had undertaken to assist Japan only if she were attacked. When the assault on Pearl Harbour did take place, the defendant Ribbentrop is reported to have been " overjoyed," and later, at a ceremony in Berlin, when a German medal was awarded to Oshima, the Japanese Ambassador, Hitler indicated his approval of the tactics which the Japanese had adopted of negotiating with the United States as long as possible, and then striking hard without any declaration of war.
Although it is true that Hitler and his colleagues originally did not consider that a war with the United States would be beneficial to their interest, it is apparent that in the course of 1941 that view was revised, and Japan was given every encouragement to adopt a policy which would almost certainly bring the United States into the war. And when Japan attacked the United States fleet in Pearl Harbour and thus made aggressive war against the United States, the Nazi Government caused Germany to enter that war at once on the side of Japan by declaring war themselves on the United States.
The PRESIDENT: The Tribunal will adjourn until a quarter past two.
(A recess was taken until 2.15 p.m.)
Sources: The Avalon Project