Power and money of course. The main issue was Vito's connections to politicians and judges, that the other families felt they too should have a share of them. The books mentions the commission, and why the families heads did not meet with Vito about Solozzo drug deal and Sol meeting with Vito shows a sign of disrespect, especially at his daughters wedding. Instead of having a meeting with Vito, the other families backed up Tattaglia, which doesn't make much sense until you put Barzini in the equation for the movie. The book is different, and Cuneo and Stracchi did not go after the Corleones until they refused to give up the murderer after the police started to crackdown on the families revenue. The book also tells that the other families were interested in the drug business, but wanted to make sure that Vito would back them up with his political connections. How M.P. set the story up, we get almost right down to what the story is going to be about on the surface, and thus why MP took short cuts in writing the book.


"I have this Nightmare. I'm on 5th avenue watching the St. Patrick's Day parade and I have a coronary and nine thousand cops march happily over my body." Chief Sidney Green