Barzini helped Vito arrange the meeting. Barzini sat at the head of the table. Barzini announced the "agreement" on drugs even before Vito agreed to it. I wonder why Vito didn't know before the meeting that it was Barzini all along. The novel tells us Barzini was younger than the other Dons, regarded them as "Moustache Petes," was impatient with being the Number Two Don...and didn't Vito know all along, before the meeting, that Tattaglia was a pimp; alone he could never have outfought Santino?

As for Barzini: he made the mistake common in the trilogy of underestimating his enemy. Vito underestimated Solozzo; Sol and McCluskey underestimated Michael; Michael underestimated Roth; Roth underestimated Michael; Zasa underestimated Vincent; Michael underestimated Altobello...