Well, sacking Constantinople was a bad idea in hindsight.
Well, no, letting the Doges of Venice run a Crusade was a bad idea in hindsight, given they had a long standing feud with the Byzantine imperial family. And the Byzantines deliberately provoking the besiegers, and all of that.
But what I found interesting about the whole thing, from my own research, is that it was the Latins, not the Byzantines, who were most critical of the rapes and looting and massacres in the sack of Byzantium. The Byzantines mostly limited their complaint to the fact Hagia Sophia was desecrated—because in Byzantine culture, rape, looting, and massacre was just
what you did in warfare. They almost wouldn’t understand anyone suggesting something like the Peace of God’s attempt to limit attacks on noncombatants.
You get a similar idea in China; it’s only very recently that China, or the countries it’s influenced like Japan or Korea, have even
had the concept of “war crime”. To them, once you’re at war, anything you do to the enemy is just, y’ know,
war.