What finaly led the untied states to enter word war 2

The surprise attack on Pearl Harbor by the Japanese led the United States to enter World War II.

Explanation:

a u.s. citizen has to have lived in and been an american citizen for a year or more be for he or she can vote for presidential or country wide elections. they also have to register to vote. if the voting is for state representatives or issues, they have to have lived in that state for one month or more and meet the requirements for country wide elections.