Mae govannen, Gandalf.
From my understanding, garnered from few books on the Crusades, most recently “A Concise History of the Crusades”, the Fourth Crusade was a bit of a disgrace. It started with high hopes, and an order for transport for lots of people, only half of whom showed up. To prevent the kind of problems that occurred in previous Crusades, Pope Innocent forbade the Crusaders from attacking any Christian city. Of course…they did. When they couldn’t come up with the money for the boats they had ordered, they made a deal with the Venetians to attack a nearby city, thus incurring excommunication. Somewhere along the line, for practical purposes, I’m sure, they were pardoned.
Meanwhile, the son of the deposed emperor of Byzantium had approached a representative and made great promises of reunification between east and western churches and monetary and military support to the Crusade if they would only help him regain power, a measure which he assured them would be welcomed by the citizens of Constantinople. It didn’t quite work out like that…the citizens were used to coups, and quite happy with the status quo. Nonetheless, they managed to get this kid back on the throne. The new emperor didn’t have the funds to make good on his promises though, and bad blood was once again sparked between the Greeks and the Crusaders, ending in the death of the young king, his father, and a new emperor on the throne, followed by a full force attack by the Crusaders, which was ALSO condemned forcefully by the Pope, though those in charge did not let this become known to the rank and file.
So where did the Pope stand in all this? Clearly, he was against the crimes committed against fellow Christians, and condemned them at every turn. He was, no doubt, an idealist, as we are all called to be in a way. The Church and the Pope asks us to say no to sin every day, in all kinds of difficult ways. That isn’t naive or dimwitted of him, that’s his job. It seems to me that the crusade would have had a much greater chance of success (as it was, almost none of the Crusaders reached the Holy Land) if they had just listened to the Pope, instead of attacking people who were supposed to be their allies. The Pope hoped for an army of saints…or aspiring saints, anyway. Remember that the Crusaders usually went to vast personal expense with little hope of worldly recompense for the sake of these ventures. The Crusaders thought they were being pragmatists, keeping the Crusade from failing, so they ignored his threats. That isn’t really a stain on the Pope as much as the Crusaders. Also, the promise of reunification offered by the erstwhile Easter Emperor must have been more than any pontiff or ecclesiastic could resist. The Schism was yet fresh in everyone’s minds, and it seemed here was a chance to heal the breach before it became hardened with the scar tissue of time.
It’s a complex issue, but I think it’s silly to hold the Pope of all people at fault for the failure of the Fourth Crusade.