Concern over US interference in their territorial ambitions, as well as being diplomatically pressure by the Western Axis forces.
To eliminate the US from interferring with their plans of conquest in the Pacific and Asia.
Japan's incursion into Manchuria, the US embargo of oil to Japan and the attack by Japan on the US Fleet at Pearl Harbor.
The aim of the Pearl Harbor attack was to cripple the US Pacific Fleet so that the US would not have any opportunity to wage war against Japan. The US would then realise it could not defeat Japan and make peace without the need to fight a war. This strategy failed because the attack enraged the US, ensuring that it would fight Japan, and because it failed to completely cripple the US Pacific Fleet (in particular, none of the aircraft carriers were damaged, and all of them would be used against Japan).
Japan attacked the U.S on December 7th 1941 at Pearl Harbor---the largest U.S naval base in the Pacific
pacific ocean!
In a brief explanation, the U.S. declared war on Japan due to Japan's attack on Pearl Harbor and other battles in the Pacific. Japan, at the time, was allied to Germany, so Germany declared war on the U.S.
Japan and the US.
The aim of the Pearl Harbor attack was to cripple the US Pacific Fleet so that the US would not have any opportunity to wage war against Japan. The US would then realise it could not defeat Japan and make peace without the need to fight a war. This strategy failed because the attack enraged the US, ensuring that it would fight Japan, and because it failed to completely cripple the US Pacific Fleet (in particular, none of the aircraft carriers were damaged, and all of them would be used against Japan).
The Japaneze bombed Pearl Habour on December 7th 1941 The US got involved in WWII by the Japanese attack on Pearl Harbour (Japan attacked the US as they saw them as a threat to there growth in the pacific and Pearl Harbour was the US main Pacific military port); as Germany was Japan's ally they declared war on the US for no apparent reason other than that Hitler thought it was a good idea. So the US joined Britain in the Allies and joined the fight against the Nazis and Britain helped the US attack Japan.
World War 2. Japan Bombed Pearl Harbor.
Japan wanted US out of the out Pacific
The US declaration on war caused Adolf Hitler of the German Third Reich declared war six days later so the Japanese attack motivated Hitler.