The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941.

I have said this before, but I shall say it again and again: your boys are not going to be sent into any foreign wars.

Many Americans opposed involving the United States in another war.

The U.S. navy conducted "shoot [Germans] on sight" convoys - convoys that might include British ships — in the North Atlantic along the greater part the shipping route from the United States to Great Britain, even though German U-boats had orders to refrain (and did refrain) from initiating attacks on U.S. shipping. The United States and Great Britain entered into arrangements to pool intelligence, combine weapons development, test military equipment jointly, and undertake other forms of war-related cooperation...

Roosevelt’s primary motivation was not altruism or disinterested generosity. Rather, Lend-Lease was designed to serve America’s interest in defeating Nazi Germany without entering the war until the American military and public was prepared to fight.

Churchill repeatedly attempted to convince Roosevelt to enter the war.

Though President Roosevelt wanted to provide assistance to the British, both American law and public fears that the United States would be drawn into the conflict blocked his plans. President Roosevelt had to develop an initiative that was consistent with the legal prohibition against the granting of credit, satisfactory to military leadership, and acceptable to an American public that generally resisted involving the United States in the European conflict.

Roosevelt is a little jealous of Winston’s place in the centre of the picture. I tell him they should have a meeting. R. is not an organiser—very like Winston—and co-ordination of effort is not conspicuous. Hull is loquacious but very sound and clear-minded about the war—much clearer than many of the officers of his department. He and all the leading ministers, are for war and nothing less. But the President, trained under Woodrow Wilson in the last war, waits for an incident, which would in one blow get the USA into war.

Edited by historian George Nash, Freedom Betrayed: Herbert Hoover's History of the Second World War and Its Aftermath is a searing indictment of FDR and the men around him as politicians who lied prodigiously about their desire to keep America out of war, even as they took one deliberate step after another to take us into war.

The memo outlined the general situation of several nations in World War II and recommended an eight-part course of action for the United States to take in regard to the Japanese Empire in the South Pacific, suggesting the United States provoke Japan into committing an "overt act of war".

The U.S. government also provided military and other supplies and assistance, including warplanes and pilots, to the Chinese, who were at war with Japan. The U.S. military actively engaged in planning with the British, the British Commonwealth countries, and the Dutch East Indies for future combined combat operations against Japan. Most important, the U.S. government engaged in a series of increasingly stringent economic warfare measures that pushed the Japanese into a predicament that U.S. authorities well understood would probably provoke them to attack U.S. territories and forces in the Pacific region in a quest to secure essential raw materials that the Americans, British, and Dutch (government in exile) had embargoed.

There might develop from the embargoing of oil to Japan such a situation as would make it not only possible but easy to get into this war in an effective way. And if we should thus indirectly be brought in, we would avoid the criticism that we had gone in as an ally of communistic Russia.

It is generally believed that shutting off the American supply petroleum will lead promptly to an invasion of the Netherlands East Indies... it seems certain that, if Japan should then take military measures against the British and Dutch, she would also include military action against the Philippines, which would immediately involve us in a Pacific war.

President Franklin Roosevelt seizes all Japanese assets in the United States.

Expecting to lose a war with the United States—and lose it disastrously—Japan's leaders had tried with growing desperation to negotiate. On this point, most historians have long agreed. Meanwhile, evidence has come out that Roosevelt and Hull persistently refused to negotiate.

On January 27, 1941, Grew secretly cabled the United States with information gathered from Ricardo Rivera Schreiber, Peruvian Minister to Japan, that "Japan military forces planned a surprise mass attack at Pearl Harbor in case of 'trouble' with the United States", information that was declassified twelve years later.

A declassified memo shows that Japanese surprise attack was expected.

Comprehensive research has shown not only that Washington knew in advance of the attack, but that it deliberately withheld its foreknowledge from our commanders in Hawaii in the hope that the "surprise" attack would catapult the U.S. into World War II. Oliver Lyttleton, British Minister of Production, stated in 1944: "Japan was provoked into attacking America at Pearl Harbor. It is a travesty of history to say that America was forced into the war."

The attack led to the United States' entry into World War II.

The United States was not the disinterested champion of democracy in the face of dictatorship: its role in the war was determined, rather, by the interests of its corporations and of its social, economic and political elites.