Something strange or maybe me, but I tried to write in Vooch -the other poster on this subject. It came up as Vouch. Yes, the massive power of organized Christendom could have re taken Constantinople. I understand the schism almost started off a conflict between the two great Christian powers.
A sad situation, and the last chance for a unified “Western” Christianity to stop the Muslims before the breakup of the western Church (with Protestants in various countries). Eventually different sides in the struggles between Catholics and Protestants would ally with the Turks as needed/convenient, thus guaranteeing Islam would be a permanent presence in Europe...
(The “Vouch” may have been an auto-correction)