Like I say, I think it was a combination of Fredo being the black sheep due to his simplicity AND the after shock of being with the Don when he was shot. You have to admit, his being constantly left out from that point on, went a long way in his relationship souring with Michael.
Yeah. Plus how would he feel if he knew right then and there that his brother and NOT him was going to take care of the people who shot his father as he fumbled and bumbled the gun.
Which begs many other questions. Had Sonny lived, would he have been as impersonal with Fredo as Michael was ?
Sonny never really interacted with Fredo. Sonny would have been closer with Fredo I believe.
Would Sonny have included Fredo more in the family business ?
More of the same... non important stuff I believe.
Would Fredo have betrayed Sonny as he did Michael ?
This is tricky... Sonny was oldest and WAS SUPPOSED to be DON. Fredo could have lived with that.... BUT when Sonny dies... Fredo was next in line "I am your older brother and I was skipped over".... that therein lies the "Fredo problem"... so No... Fredo wouldnt betray Sonny IMO
And the big one, would Sonny have ordered the death of Fredo ?
I dont think it ever comes down to betrayal of Sonny because Fredo looked at Sonny as Don as the right thing. (per my above answer)... but if I had to answer... No way Sonny kills Fredo... he detaches from him at worst
