He advocated African-American independence, pan-Africanism, and the idea that African-Americans should return to Africa. It was because he believed that they would be free there because the United States were a country where people are being oppressed and he wanted to end that.
The main goal of the bombings at Pearl Harbor was to frighten the United States from entering the war as they had stationed much of their Pacific fleet at Pearl Harbor. This was perceived as a threat to the imperial ambitions of Japan.