Instead of seeking revenge for Sonny's killing, Don Corleone meets with the heads of the Five Families to arrange an end to the war. Not only is it draining all of their assets and threatening their survival, but ending the conflict is the only way that Michael can return home safely. Reversing his previous decision, Vito agrees that the Corleone family will provide political protection for Philip Tattaglia's traffic in heroin. At the meeting, Don Corleone realizes that Don Barzini, not Tattaglia, was responsible for the mob war.With his safety guaranteed, Michael returns from Sicily. More than a year later, he reunites with his former girlfriend, Kay, telling her that he wants to marry her. With the Don semi-retired, Sonny dead and middle brother Fredo considered incapable of running the family business, Michael is now in charge, and he claims that the family business will soon be completely legitimate.