Image Sources: US Air Force Museum

Account of Secretary of State Cordell Hull of activities on December 7, 1941, following Japanese attack on Pearl Harbor Shortly after three o'clock I went to the White House, where I talked with the President and others for forty minutes. Mr. Roosevelt was very solemn in demeanor and conversation. The magnitude of the surprise achieved by the Japanese at Pearl Harbor was already becoming evident But neither he nor any of us lost faith for a moment in the ability of the United States to cope with the danger. We had a general discussion preparatory to a conference that the President decided to hold that evening with Stimson, Knox myself General Marshall, Admiral Stark, and other principal advisers. We discussed in a tentative way the many different steps that would have to be taken, when and by whom. The President early determined to go to Congress with a message asking for a declaration of a state of war with Japan. The Memoirs of Cordell Hull, Spartacus Educational

The Japanese attack on Pearl Harbor on December 7, 1941, that brought the United States into World War II was preceded by a steady deterioration of relations as the Roosevelt Administration sought to slow Japanese expansion in the Pacific.

In July 1940, in response to Japan's invasion of Manchuria, President Roosevelt ordered a ban on American trade with Japan, a move that led to the Japanese seeking additional resources from other parts of Asia to support industrial and military expansion. Japan then invaded the British and Dutch colonies in Southeast Asia followed by attacks on French Indochina in September. In July 1941, all Japanese assets in the United States were frozen. Similar action by Great Britain and the Netherlands affected shipments of oil from the East Indies. This created such a critical situation for Japan that its cabinet decided that, unless the United States made concessions, the oilfields to the south would be seized by military operations.

Diplomatic exchanges between American and Japanese officials continued through December 7. the Casualities to U.S. service personnel were 2,343 killed, 960 missing, and 1,272 wounded; 151 U.S. planes destroyed on the ground and all eight U.S. battleships at anchor in Pearl Harbor were either sunk or damaged. At a cost of only 28 airplanes shot down, the Japanese had dealt the U.S. a staggering blow. See The Pearl Harbor Attack, United States Air Force Museum. On the following day, President Roosevelt formally requested that the Congress declare war in the famous speech that began: "Yesterday, Dec. 7, 1941 - a date which will live in infamy - the United States of America was suddenly and deliberately attacked by naval and air forces of the Empire of Japan."

While the Roosevelt Administration's policies toward Germany, Japan and the other Axis powers prior to December 1941 were heavily influenced by the substantial isolationist sentiment against the U.S. entering a war, the attack on Pearl Harbor allowed the President to use the strong public reaction to forge a united effort to mobilize the country for war. See The Day after the Day of Infamy, Man-on-the-Street Interviews after Pearl Harbor, Library of Congress. Such former isolationist critics as the America First Committee also came on board to back the U.S. entry into the War, with the AFC executive board voting four days after Pearl Harbor to dissolve the organization, announcing that "The time for military action is here."

Left: Man and woman working together adjusting the controls of P-51 Mustang fighters for the United States Army Air Forces on final assembly line at North American Aviation Co. plant. Image Source: Library of Congress

Right: Recruitment poster seeking women to work as government stenographers. Image Source: National Archives & Records Administration

The internment of Japanese Americans was implemented despite intelligence reports that the vast majority were loyal to the U.S., as indicated in the excerpt below from a memo to the Chief of Naval Operations.

From: Lieutenant Commander K.D. RINGLE, USN.
To: The Chief of Naval Operations.
Via: The Commandant, Eleventh Naval District.
Subject: Japanese Question, Report on.

...The primary present and future problem is that of dealing with those American-born United States citizens of Japanese ancestry, of whom it is considered that least seventy-five per cent are loyal to the United States. The ratio of those American citizens of Japanese ancestry to alien-born Japanese in the United States is at present almost 3 to 1, and rapidly increasing....

That, in short, the entire "Japanese Problem" has been magnified out of its true proportion, largely because of the physical characteristics of the people; that it is no more serious than the problems of the German, Italian, and Communistic portions of the United States population, and, finally that it should be handled on the basis of the individual, regardless of citizenship, and not on a racial basis....

Source: The Densho Project

Although recognizing that the wide-ranging internment of Japanese Americans affected many loyal citizens, the Supreme Court declined to interfere with the military's judgment under the threat of attack.

...Compulsory exclusion of large groups of citizens from their homes, except under circumstances of direct emergency and peril, is inconsistent with our basic governmental institutions. But when under conditions of modern warfare our shores are threatened by hostile forces, the power to protect must be commensurate with the threatened danger....

Source: Opinion for the Court of Justice Hugo Black,

Korematsu v. United States