I didn't know until this day that it was Barzini..

If Vito didn't know until "this day" (meaning until the end of the Dons' meeting) that it was Barzini all along, Barzini must have given clues to Vito. I think it was the way he tried to fix the agreement on drugs. "A refusal is not the act of a friend..."

Was Barzini too self-confident? Could he have kept his guard if he had let do the other Dons like Zanucchi the job? Or even better: Acknowledge the dilemma and pretend to be undecided.

I think he was mistaking vitos willingness for a peace agreement and him not wanting to seek vengence for santino as a sign of weakness. I think its pretty obvious(at least to me it is) that he views himself as the most powerful boss at the meeting, the way he was seated at the head of the table and was talking to every1 like he was in charge. So yes he was way to confident and gave him self away. But from vitos other comment "tattligia's a pimp, he couldve never out fought santino" it seems he already had his suspicions.

Barzini's confident, commanding demeanor at the meeting was a conscious act on his part to establish himself as Vito's successor as Number One in the Five Families. But Vito set him up, in a way, by asking him to help arrange the meeting ("I want to thank Don Barzini for helping me to arrange this meeting").

The surprising thing is that Vito didn't know until that day that it was Barzini all along. "Tattaglis is a pimp...alone he could never have outfought Santino." Shouldn't that have been obvious to Vito from the beginning?

I think that Vito initially believed that Barzini got involved after the killing of Solozzo and Sonny ,at the request of Tattaglia.

It would have made sense to Vito that a weaker Don like Tatt would seek intercession from Barzini,both to end the killing,and to get Vito's co-operation in the drug trade.

After observing Barzini's demeanor at the meeting,Vito realized that Barzini's involvement went back to the very beginning,and that Tattaglia was never anything but Barzini's pawn from day one.

I think Vito may have thought Barzini aligned himself with Tatt as did the other families in the war with Sonny, but that Barzini was not leading the charge. In fact Barzini may have pulled his punches until he secretly ordered the murder.

IT would be logical for Vito, whether he suspected Barzini or not to use him as the intermediary to set the meeting, because in theory the war was between the Tattaglias and the Corleones. They killed Luca, Sonny killed Tatt Jr., and Sollozzo led everyone to believe that the tattaglias were in for a cut of the drig money, which he would pay out of his share.

The dead giveaway at the meeting came after Vito made his compromise on restricting the sale of drugs, and Barzini then announced the terms of the peace to everyone. At that point Tatt turned to Barzini and asked him what assurances he had that once the Corleones gained strength they wouldn't come after him again. The fact that he asked Barzini this, and that Barzini assuaged his concern, made it perfectly clear that he was controlling the whole thing, and had been from the beginning. Thats why it was not until that day that Vito did not understand it was Barzini "all along."

I always got the impression that Barzini was always behind the Sollozzo thing and was using the Tattaglia's as front.

I also thought Coppola was letting us in on it early when he showed Barzini having his goon grab the photographer who took his picture at the wedding the way he did. It struck me a s subtle show of disrespect to Don Vito right at his home.

I thought the cold embrace of Vito and the flat look on Barzini's face were very revealing. Having his thug grab the photo was a very nice touch. It's one of those details that makes the wedding scene one of the best in the Trilogy.

Maybe Vito was in denial. It is very clear that Barzini was an up and coming Don, not one of the Moustache Petes with whom Corleone had dealt over the years. Maybe he either didnt see hoim coming or maybe he underestimated him.

Would Vito & Michael still wipe out the commission if Barzini didn't give himself away at the meeting?

I think even though Vito knew tattaglia was a pimp & could never out fought Sonny, he couldn't really prove who was backing him, only assumptions or until someone slips up...like Barzini.

I guess it was smart to call a peace meeting, then present yourself as week and surrendering..to flush out the enemies confidence.