What if Constantinople had never fallen to the Turks?

[Madae]

The city would have never been sacked if it was a Catholic kingdom. That was the whole point of the crusades; for Christian's to come together and fight a common enemy. Anyone who wasn't Christian was fair game. The west would also have been a lot more eager to defend it should it have come under attack. The Turks may not have even tried to invade.

The Italian's also recognized that Constantinople was the key to eastern trade and beyond, and they were very interested in keeping that prospect open. The door was practically shut on eastern trade for the western kingdoms when Constantinople fell, which is partially the reason why Columbus sailed west into the Atlantic to find a trade route that bypassed the Muslim kingdoms altogether.

Ultimately, we'll never know the answer and what would really happen if Constantinople never fell. This is all just speculation. To say anyone and their opinion is wrong, or even doubtful, is kind of silly. You can argue it, but don't assume to know what is and isn't. A better way to word that would have been to just leave out the "I doubt it" part. Just a thought.