Originally posted by AppleOnYa:
If Sonny remained alive then there would've been NO GFII, because he would've run the Corleone Family into the ground before Michael ever had the chance to touch it.
One of the main underlying themes of The Godfather was that Sonny, the eldest son and heir apparent, HAD to die so that the Family would ultimately end up under the guidance of the youngest and least likely son.
Apple
Precisely. If Sonny had lived he wouldn't have had the ability to bring Michael home from Sicily, and I would guess eventually Michael would have ben assassinated there.
Tom was going to fight the war to the bitter end regardless of the consequences. Tessio would have betrayed the family, and Clemenza just might have gone along with Tessio.
Tom would either jump ship or be shoved off for always trying to patch things up and the Corleone family would have been a distant memory.