After the events of the First World War, which left Japan as the most powerful Navy in the Asian coast, this country aimed for supremacy along all of the Pacific Ocean, as well as control of many territories through Southeast Asia in order to obtain sourcing points for their industrialization strategy.
They planned to materialize these ambitions with the Attack on Pearl Harbor on December 7th, 1941. This was seen as a dreadful act by the United States, as the Japanese Empire had not issued an official declaration of war against the country.
In order to stop Japan's imperialization efforts in the Pacific, the United States, as the only country who could realistically militarily neutralize Japan decided to declare war on them on December 11th, 1941.
