The start of this controversy started in 1900 when Secretary of State John Hay made two notes known as the Open Door Policy. The first not was to provide equal access to commercial right in China for all nations. The second said for all countries to respect Chinas territorial and administrative integrity. In 1922 the restatement of the Open Door policy came onto the Nine Power Treaty agreeing to assist China in forming a stable government. Japan supported the agreements because of worldwide economic stability this would take a turn for the worst as a worldwide depression would reach in 1931. Japan was now looking to expand there political and economic influence on China as on Sept 18th 1931 the Japanese army over-ran Chinese troops stationed in South Manchuria.
The League of Nations condemned Japans actions and the Japanese withdrew from the League. President of the United States Franklin Roosevelt specifically announced that there would be no U.S. involvement in any military action not in the U.S. Then in 1937 a full scale battle broke out between Japan and China which in-turn China receiving only nonmilitary aide from the U.
S. This then involved many conflicts between the U.S. and Japan regarding the involvement of U.S. in any stature.
Japan, Germany and Italy signed the Tripartite Treaty on Sept 1940. Under that treaty war with Japan, meant with Germany and Italy. Many pressures increased on Japan when the United States froze of all Japanese assets and trade with the U.S., Great Britain, and the Netherlands, the extension of financial and military aid to China in concert with Great Britain and the Netherlands which started early in 1941. Then more pressure came upon the Japanese when Roosevelt gave unmistakable evidence that he was not worried about the Pacific Fleets effects upon Japanese diplomatic decisions when he authorized the weakening of the fleet, already inferior to that of Japan by the detachment of 3 battleships, 1 Aircraft carrier, 4 light cruisers and 18 destroyers for duty in the Atlantic.
A movement in which Japanese spies in Hawaii would certainly notice. U.S. Cryptanalyst had much success in reading code used by the Japanese. At the same time Japanese Cryptanalysts also had success in reading our code involving movement in our Fleets. At this point you would suppose a military act against the U.
S. in some way. Maybe not a specific threat (Location, time ect.) but would cause an alert for military to be on guard for a military movement against the United States by the Japanese. Meaning not weakening forces in the Pacific leaving Pearl Harbor an open area for attack. Roosevelt also knew from ongoing treaty tries with the Japanese that this was the last straw with the Japs.
Also pure evidence that the attack was happening when Ambassador Grew a political analyst in Tokyo overheard a conversion with diplomatic leaders that there will be an attack on Pearl Harbor. At first we did not know if there would be an attack, or where or where. Now we have evidence that it will happen. Roosevelt still refused and Japanese involvement because of specific details that were excluded from Grews statement. Obviously we had information regarding an attack on Pearl Harbor. Some say President Roosevelt withheld information from Admiral Kimmel, the Pacific Fleets commander, so that an attack would inevitably bring U.
S. into a war with the Japanese. The attack would then be a prelude to the defeat of the Axis Powers.
With all this information and facts .