Friday
“A night interrupted by Ribbentrop’s restlessness. After delaying two days, now he cannot wait a minute to answer the Japanese and at three in the morning he sent Mackenson to my house to submit a plan for a triple agreement relative to Japanese intervention and the pledge not to make a separate peace. He wanted me to awaken the Duce, but I did not do so, and the latter was very glad I hadn’t * * *.” (2987-PS)
It appears from the last entry that some sort of agreement was reached. On Sunday, 7 December 1941, Japan without previous warning or declaration of war commenced an attack against the United States at Pearl Harbor and against the British Commonwealth of Nations in the Southwest Pacific. On the morning of 11 December, four days after the Japanese assault in the Pacific, the German Government declared war on the United States. (2507-PS)
The same day, 11 December 1941, the Congress of the United States resolved that “the state of war between the United States and the Government of Germany which has thus been thrust upon the United States is hereby formally declared”. (2945-PS)
It thus appears that, apart from their own aggressive intentions and declaration of war against the United States, the Nazi conspirators in their collaboration with Japan incited and kept in motion a force reasonably calculated to result in an attack on the United States. While maintaining their preference that the United States not be involved in the war at the time, they nevertheless foresaw the distinct possibility, even probability of such involvement as a result of the actions they were encouraging; they were aware that the Japanese had prepared plans for attack against the United States; and they accepted the consequences by assuring the Japanese that they would declare war on the United States should a U.S.-Japanese conflict result. In dealing with captured documents of the enemy, the completeness of the plan is necessarily obscured. But those documents which have been discovered, and introduced into evidence before the Tribunal, show that the Japanese attack was the proximate and foreseeable consequence of their collaboration policy, and that their exhortations and encouragement of the Japanese as surely led to Pearl Harbor as though Pearl Harbor itself had been mentioned.
The entry in the Ciano Diary for 8 December 1941 gives an interesting sidelight on Ribbentrop’s reaction to the Japanese sneak attack:
“December 8.
Monday.
“A night telephone call from Ribbentrop; he is overjoyed about the Japanese attack on America. He is so happy about it that I am happy with him, though I am not too sure about the final advantages of what has happened. One thing is now certain: that America will enter the conflict, and that the conflict will be so long that she will be able to realize all her potential force. This morning I told this to the King who had been pleased about the event. He ended by admitting that in the “long run” I may be right. Mussolini was happy too. For a long time he has favored a definite clarification of relations between America and the Axis.” (2987-PS)
A conference was held between Hitler and Japanese Ambassador Oshima on 14 December 1941, from 1300 to 1400 hours, in the presence of the Reich Foreign Minister, Ribbentrop. The subject matter was the Pearl Harbor attack. The top secret notes of this conference read in part: