plinytheelder_t at 2012-09-22 02:32:47:
I'm not so sure I agree 100% with Jason's analysis.
It's clear from his first scene that while Michael is a "civilian", he's deeply cognizant of what his family does and how it operates. In that scene, the phrase "That's my family, Kay. It's not me", sets up Michael's fundamental internal conflict, because if you participate in your family then it's inextricably part of you.
Similarly Michael shows an understanding of the nuances of NY gangland life when he talks about Tom Hagen eventually becoming a consigliere despite not being a Sicilian, even though he accepts him as a brother. We can see that the gangster life is fundamentally part of Michael's makeup even if he chooses not to participate.
Over the course of the film we see that of all the sons, he is the most like Don Vito. But he also shows signs of being both Sonny and Tom's brother (Sonny's anger and need for revenge; Tom's calculating nature) and the anti-Fredo.
Consequently, however hard he tries to escape the bonds of his background and his family, Michael is someone who's doomed into falling back to his true nature: that of a Sicilian man.
For example, when he's exiled in Sicily, Michael falls for Apollonia like "Un colpo di fulmine" (a flash of lighting): a Sicilian girl. Contrast this with his relationship with Kay, who he seems to love, but as evidenced by the kitchen scene with Clemenza ("Mikey, why don't you tell that nice girl you love her?"), it's a passionless love he can't quite bring himself to acknowledge. Especially after he returns from Sicily, you get the sense Michael's settling for Kay in order to form his own family unit.
In the end, like his father, Michael has no choice but is compelled and trapped by obligations of family: those same obligations he tried to escape earlier in his life but ultimately cannot. His instincts and motives, are those of a Sicilian: family, revenge, blood, distrust of strangers, omerta.