Did Japanese declare war after Pearl Harbor started?

Answer 1

no, the united states declared war on Japan after pearl harbour

The official declaration of war by the Empire of Japan on both the United States and the British Empire was released on December 8, 1941 after the pre-emptive attack on Pearl Harbor was completed. The attack took place before any formal declaration of war was made by Japan, but this was not Admiral Yamamoto's intention. He originally stipulated that the attack should not commence until thirty minutes after Japan had informed the United States that peace negotiations were at an end. The Japanese tried to uphold the conventions of war while still achieving surprise, but the attack began before the notice could be delivered.

Tokyo transmitted a 5,000-word notification (commonly called the "14-Part Message") in two blocks to the Japanese Embassy in Washington, but transcribing the message took too long for the Japanese Ambassador to deliver it in time. The final part of the "14-Part Message" is sometimes described as a declaration of war, but in fact it "neither declared war nor severed diplomatic relations". All it really did was notify the US that peace negotiations were at an end. The actual declaration of war was printed on the front page of all newspapers in Japan in the evening edition on December 8 (Japan time, December 7 in the United States) but not delivered to the U.S. government until the day after the attack.

In 1999 a professor of law and international relations at the International Christian University in Tokyo, discovered documents that pointed to a vigorous debate inside the government over how, indeed whether, to notify Washington of Japan's intention to break off negotiations and start a war, including a December 7 entry in the war diary saying, "our deceptive diplomacy is steadily proceeding toward success." Professor Iguchi said, "The diary shows that the army and navy did not want to give any proper declaration of war, or indeed prior notice even of the termination of negotiations."