After the Commission meeting, Vito tells Tom, "Tattaglia is a pimp--he could never outfought Santino alone. But, until this day, I never knew that it was Barzini all along."

DUH, Vito: How could you not know it was Barzini all along??? Since Tattaglia was a pimp, and could not have outfought Santino alone, why wouldn't you have figured out, long before the Commission meeting, that someone else was orchestrating the war--and that someone else was Barzini? He was younger than the other Dons, more ambitious, anxious to be Numero Uno in the NYC Mob scene. And, if you had known it, you could have advised Sonny on how to best direct his forces--maybe winning the war and even saving Sonny's life?

Your thoughts?.

In fairness Vito was recovering from his attack up until that commission meeting. So who knows if he had time to even strategize or think clearly

Also, I think that Vito's words were meant more as a confirmation than an epiphany.

Also, Tom's surprised response: "You mean Tattaglia?" strongly suggests that in all the time he was recuperating, he never discussed the issue or his suspicions with his Consiglieri.

I think that Vito knew that someone was supporting Tattaglia in the war. I think that "Barzini all along" means that Barzini was the instigator who brought the war about.

Vito's slip ups, believing among others -

• the minting money Narcotics deal offer was just between Sollozzo, Tattaglia and the Corleones only
• Barzini and the other families wouldn't want a piece of this lucrative deal - 30% share alone should be three, four million dollars just in the first year
• Sollozzo would just accept Vito's refusal No repercussions
• As we'd debated before - perhaps biggest slip up was sending Luca over to Tattaglias which nobody Tom, Sonny, nobody knew about, thus to Luca's death, losing the Corleones feared Enforcer, one man killing machine

Also, Vito
1. didn't up his personal protection
2. didn't smell a rat when Paulie was calling in sick
3. had Fredo -- well -- Fredo was -- well – as his Bodyguard / Driver

As regards Sonny's death, I doubt anyone would have seen it coming from Carlo
Also as Tom said "Things are starting to loosen up a little bit" as well perhaps lulling everyone into a false sense of security

side question please
Why would Sonny think Tattaglia's [who are way down in the pecking order] guarantee is a big deal?

Lana, that script line was written for effect--to set up Vito's shooting by highlighting Sonny's greed for the deal in seeming defiance of his father's "no" - the "ch**k in Vito's armor," as the novel puts it. But, if you take Sonny's question at face value, he's being skeptical, like you, as to how the Tattaglia's could guarantee the million dollars Sol wanted from Vito when, if they had a million dollars, Sol could have gotten it from them?

No doubt to keep the story rolling, threads going, keeping the board active!
It caught Sollozzo's attention that Sonny was hot for his deal

Good point Turnbull The reasonable inference is that he couldn't get the million which was just finance for Vito, from Tattaglia yet as you say if they had a million dollars or could guarantee why couldn't Sol have gotten it from them?

slippery and dicey Sol says I'll take care of the Tattaglias, outta my share What is their contribution that deserve this generosity?

Guaranteeing a debt doesn't necessarily mean you have that much cash on hand at the moment. It just means that your resources are such that you could retire the debt if necessary.

As regards Sonny's death if Vito had sorted the wife beating, abusive son-in-law he would not have been forced to get involved thus to his death

ten years ago Vito would have figured out it was Barzini all along."
Didn't know that someone was supporting Tattaglia until the meeting No suspicions

Didn't tell his no decision to Underboss Sonny, Consiglieri Tom Didn't discuss sending Luca over to Tattaglias

No sorting daughter domestic violence resulting in Sonny death

Sollozzo was piling on the flattery on Vito and Tom too
Also smug the Corleones hadn't found out Barzini's connection that it was Barzini all along

I believe Vito's million was insurance ie: Vito's own money invested - for Vito's commitment and guarantee that he wouldn't change his mind and pull the plug on his protection
I think everyone would have had to invest some money of their own

Whilst I appreciate Sollozzo may have been “very, very scared he botched” Vito's murder, did Sollozzo really think Sollozzo could string the Corleones along until third time lucky! even without Luca -
1. killing Vito
2. kidnapping Tom to persuade Sonny to make peace as if...
3. threatening Tom on finding out Vito had survived
4. meeting with civilian Michael to buy time

Then again if not for Michael....

same as Havana two million

if not for Michael....Vito dead

on further review! considering the Tattaglias are number 3 at best, Tattaglia's guarantee of the “Numero Uno in the NYC Mob scene” Corleones' investment perhaps eerily not dissimilar to

C-note from the Rosatos, guarantee from the Tattaglias - oranges! foreshadowing their hits
Oh, well! Both Vito and Pentangeli survived....