10 Dec. 45

Berlin before giving a reply. The Duce was pleased with the communication and said, 'We are now on the brink of the inter-continental war which I predicted as early as September 1939.' What does this new event mean? In any case it means that Roosevelt has succeeded in his maneuver. Since he could not enter the war immediately and directly, he entered it indirectly by letting himself be attacked by Japan. Furthermore, this event also means that every prospect of peace is becoming further and further removed and that it is now easy — much too easy — to predict a long war. Who will be able to hold out longest? It is on this basis that the problem must be considered. Berlin's answer will be somewhat delayed because Hitler has gone to the southern Front to see General Kleist, whose armies continue to give way under the pressure of an unexpected Soviet offensive."
And then December 4, Thursday-that is 3 days before Pearl Harbor:

"Berlin's reaction to the Japanese move is extremely cautious. Perhaps they will accept because they cannot get out of it, but the idea of provoking America's intervention pleases the Germans less and less. Mussolini, on the other hand, is pleased about it."
And December 5, Friday:

"A night interrupted by Ribbentrop's restlessness. After delaying 2 days, now he cannot wait a minute to answer the Japanese; and at three in the morning he sent Mackensen 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 had not."
It appears from the last entry I have read, that of December 5, that some sort of an 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, 4 days after the Japanese assault in the Pacific, the German Government declared war on the United States, committing the last act of aggression which was to seal their doom. This declaration of war is contained in Volume IX of the Dokumente der Deutschen Politik, of which I now ask the Tribunal to take judicial notice as Exhibit USA-164. An English translation is contained in our document book, and for the convenience of the Tribunal is Number 2507-PS.