Final answer:
Japan attacked the US at Pearl Harbor on December 7, 1941 for multiple reasons, including preventing US intervention in their expansion plans and gaining control of the US.
Step-by-step explanation:
The decision for Japan to attack the US at Pearl Harbor on December 7, 1941 was driven by several factors.
First, Japan believed that American intervention in their expansion plans was inevitable. They planned a coordinated Pacific offensive to neutralize the US and other European powers, hoping to buy time for Japan to complete their conquests and fortify their positions.
Secondly, Japan sought to deal a surprise death blow to the US Navy to prevent interference with the expansion of their empire in Asia, particularly in French Indochina and the Dutch East Indies.
Lastly, the Japanese military believed that by attacking Pearl Harbor and crippling the US Pacific Fleet, they could invade the western coast of North America and eventually gain control of the entire United States.