Exactly. That's why I think that many Board members have it wrong when they cite Michael's "I'm with you now" statement to Vito when he was in the hospital. That statement represented Michael's renouncing his estrangement from his father (such estrangement is explained in the novel and somewhat also in one of the Saga's scenes). It was not meant by Michael to represent his commitment to his father's crime family and its machinations. As you appear to point out, such commitment was, in large part, a function of Appolonia's murder and Fabrizio's betrayal.
I agree with your analysis, Oli. I don't think Michael could have envisioned himself as being an integral part of the family enterprise when he said, "I'm with you now, Pop." And in any event, Sonny was still in charge. Even his decision to whack Sol and Mac was made to protect his father against another attempt on his life (and perhaps in revenge for Mac breaking his jaw, but let's not go there now).
By the time of Appolonia's murder, Michael was no longer a "civilian" because of his murder of Mac and Sol, and was a hunted man. And, Sonny had been killed. Arguably, his decision to become the Don-in-waiting was taken because there were few if any other options available to him after that point.
Ntra la porta tua lu sangu � sparsu, E nun me mporta si ce muoru accisu... E s'iddu muoru e vaju mparadisu Si nun ce truovo a ttia, mancu ce trasu.
