Why did Japan attack Pearl Harbor? What were the reasons behind the attack?

by d_meinhale99
swedishpenis

https://www.reddit.com/r/AskHistorians/comments/2ko68f/why_did_japan_need_to_attack_pearl_harbor_when/ ^most comprehensive answer (credit to /u/thefourthmaninaboat)

https://www.reddit.com/r/AskHistorians/comments/n3wvd/what_caused_japan_to_attack_pearl_harbor_on_12741/

https://www.reddit.com/r/AskHistorians/comments/1xkkrj/why_did_japan_feel_the_need_to_attack_the_us/

https://www.reddit.com/r/AskHistorians/comments/20uxwd/why_did_japan_attack_pearl_harbor_rather_than/