...and control. That scene was a marvel of manipulation--"You're my brother, Tom." Tom, practically breaking into tears, "Always wanted to be considered your brother" -- meaning that Tom didn't think Michael considered him "a brother" until that point, after all those years. Michael needed him then. But, as soon as he came back from Havana, in charge again and knowing who the traitor was, Michael went right back to yelling at Tom, treating him as a subordinate.