Would Solozzo have gone ahead with his plan to whack Vito if Sonny hadn't shot off his mouth at the drugs meeting and shown his greed for the deal?

You know TB, I never quite understood the typical interpretation of that scene. I know that Puzo and FFC wanted it interpreted the typical way. However, being the wise guy that Sonny was, I could interpret his words as his just being a smartaleck: "Yeah, sure. The Tattaglia's are going to do us a favor. No way.

Even if Sonny never spoke those words, I could conclude that Sollozzo realized that the the only way for Sollozzo to overcome Vito's no was for Sollozzo to eliminate Vito and then see if his successor would agree,

I, too, thought Sonny was being skeptical until I saw otherwise in the book. I think Caan misread the line a bit.

I think that Sol's calculus changes if Sonny keeps quiet, but not dramatically. Vito's the one who thinks differently among this group. It can be assumed as unlikely that Sonny would be as hard line against the drug trade. Sol's main concern with respect to Sonny is how to counter his attempts at revenge, and those would come regardless of Sonny's thoughts on drugs.

Sollozzo recognizes that drugs are the way of the future and that Vito "pensa all'antiqua." It is logical that, with Vito out of the way, the rest of the Family would come along.

In fact, Sollozzo himself indicates that Tom, not Sonny, was really the key. He realizes that Tom knows it was "the right thing to do" and expects Tom to convince Sonny to go along.

Plus, Sollozzo couldn't be expected to just give up once he got Vito's refusal to help. Obviously, he would have done something.

So I think the hit happens either way.

BTW, I also agree with mustachepete that Caan kind of blew the delivery of the line. He should have sounded more interested than belligerent.

I don't understand how Caan kind of blew the line.

Logic puts me with Oli, Sol couldn't do business without Vito's money, judges and politicians, Vito said "no" to Sol, and his "no" was "final." He left Sol with two choices: either skulk back to Sicily with his tail between his legs, or whack Vito and try again with his successors.

BUT:

Killing a Don is an act of regicide. Sonny's show of greed had to be a decisive factor in Sol's convincing of Tattaglia to support the assassination, and in mollifying the other Dons. Sol had to have told Tatt and the other Dons: "Sonny is hot for my deal, and that Irish consigliere, Hagen, is hot for it too. With the old man out of the way, they'll go for my deal--and there will be no war." Without Sonny having opened his mouth, I'm doubtful that Sol could have persuaded a pimp like Tattaglia to support whacking Vito and risking an all-out war.

I suggest a corollary question TB: Since it was Barzini all along, what would Barzini do if Vito had made the deal?

I think that it would have gone this way:

Scenario A: Vito agrees to Sollozzo's idea

First, there's no hit because Vito agreed, presumably with regulations like they stated later at the Don's meeting (i.e. not by schools, kept to the black neighborhoods, etc). Barzini consolidates his power, because Barzini also has major connections just not as many lawyers/judges/politicians like Vito does. I think the end result here is that there is peace for longer (potentially much longer) but eventually Barzini can't control his ambition and something happens down the road. Now both the Barzini family and the Corleone family have gotten fat from the drug trade, so a war would likely be more brutal and more open. However, the Corleone Family at this point would have gambling, the unions AND the drugs. So I think they end up ahead as they were already the strongest family, and the money from narcotics helps them grow stronger. Michael almost certainly does not end up as the Don but probably moves away and has his whitebread family with Kay as a mathematics professor.

Scenario B: Vito refuses Sollozzo, Sonny doesn't open his mouth

This becomes interesting, because we don't know for sure what Sollozzo would have done in this case. He finds no ch*nk in the Don's armor, no hot-headed eldest son who would inherit the family if the old man dies. We know for a fact Sollozzo cannot take no for an answer, because he is a man of respect and Don Corleone's "no" means Sollozzo cannot operate his business (technically he could, but it would be at an extremely great risk without the lawyers/judges/political connections of Don Corleone), and he is not the kind of man who will let another man dictate his life. In this scenario I think Sollozzo goes to Barzini (I am not sure if at this point in time Sollozzo was talking to Barzini, or just Tattaglia; we know it was "Barzini all along" who set the seeds for the hit, but we don't know his exact involvement), who also presumably has some politicial/legal connections, and does business in a lesser scale than he originally planned, but there is no hit as it's too risky.

I think the end result here is exactly what Tom says when he suggests Vito agree: Well, I say yes. There is more money potential in narcotics than anything else we're looking at now. If we don't get into it, somebody else will, maybe one of the Five Families, maybe all of them. And with the money they earn they'll be able to buy more police and political power. Then they come after us. Right now we have the unions and we have the gambling and those are the best things to have. But narcotics is a thing of the future. If we don't get a piece of that action we risk everything we have. Not now, but ten years from now.

Barzini and maybe Tattaglia, even Cuneo and Stracci get into the trade, and "ten years from now" I think Barzini makes his power play. All hypothetical at this point, but I think in this scenario the Corleones are on the losing end. Things happen (maybe Sonny still gets whacked), the Corleones sue for peace, and Barzini becomes the most powerful family. Michael probably does not end up as the Don, but could depending on circumstances. I think in this case though he does not, and the Corleones become a minor family.

Very interesting scenarios, Wayne! Yes, Barzini is the key player. In my view:
Sol had needs--to operate with the sponsorship of one of the Five Families, $1 million in cash, and police/political protection. Any of the Families could sponsor him, but only Corleone had the cash and the police/political protection.

But Sol also had something to give to his partner: the money his partner would earn would make the partner stronger because he'd be able to buy more police/political protection. Corleone wouldn't be interested: he was already on top with rackets that weren't as risky as Sol's. So, I believe, Sol contacted Barzini first because Barzini was younger than the other Dons, impatient to be Numero Uno, had more to gain from a deal with Sol--and would give him better terms. Barzini replied, "Your logic is good. But you still need Corleone's judges and politicians. If Corleone knows that I'm your partner of record, he'll say no. Go to Tattaglia and tell him anything he wants to hear. He's a pimp. Corleone isn't afraid of him. But I'll be your partner--your silent partner--and I'll have your back at all times."

Barzini couldn't lose. If Vito said yes to Sol's deal, the money Sol channeled to Barzini made him richer and stronger. If Vito said no, then Sol would try to whack him. If Sol succeeded, Barzini automatically would become Numero Uno. If Sol failed, the Corleones would come after Tattaglia.

In any case and in any scenario, the money to be made from drugs would create uncontrollable greed. Whomever was perceived as making the most money from drugs--Sol, Vito, Barzini, Tattaglia--would become a target for the others. And even if Vito agreed to protect the drugs trade with the proviso that the others had to use discretion, keep it respectable, use couriers with clean records, greed would cause the others to violate those terms. The moment Vito refused protection, he'd become the target.

Moral: crime doesn't pay.

About a year ago, we pretty much exhausted a thread about Sollozzo's motivation for murdering Vito as a result of Sonny's gaff. In that thread and this one I opined that Sonny's gaff would not convince me that Sonny would approve the deal if I were Sollozzo. I also opined that both Puzo and FFC want us to believe that Sonny's gaff was interpreted by Sollozzo as Sonny's approval of the drug deal. So, that being the case, Sollozzo's getting rid of Vito was logical.

However, without Sonny's gaff, I still think that Sollozzo would have murdered Vito anyway at the behest of Barzini. I figure that Barzini knew that Vito would say no; Vito's No was just a cover. Barzini wanted to be number one. He was already engaged in the drug trade (as was Stracci). Barzini had the resources to sponsor Sollozzo (Vito knew that it was Barzini all along). I figure that Barzini told Sollozzo that once Vito was gone that he and the other families would support Sollozzo's inheritance of the Corleone family. Whether that would eventually happen or not is anybody's guess.