My 2 cents....
1. The fact that Catholics did worst centuries ago can't be in any way or form a reason to justify the existence of ISIS, Al Qaeda and all the other radical form of Islam as a regime and a Government. People who use the fact Christians did worse makes me wanna pull my eyebrows out tbh, it's like saying the Israelis have the right to massacre Palestinians GP because Germany did worst to them and a couple radical nut jobs Islam fanatics are threatening their national sovereignty. One can't justify the other, if we do that we are doomed. I wonder what people would think if Israel started bombing Germany out of the bloom....
2. Did you ever ask yourself why the Middle East is a concern while so many Islam-Fascist regimes are installed in Africa??
3. Radical Islam is NOT a religion first, that's the issue. Is most of all a regime, the law which the State will operate and rule society with. Comparing it with Christiniaty is naive and not reading between the lines. Radical Islam is closer to Fascism and Nazis than to Christianity in this time and age. There ins't shades of grey in Radical Islam as a State, you are in or you are dead, that's the 2 options. There isn't a choice. That's a regime, that's fascism.
4. Radical Islam is a lot worse then Christianity (Catholic) was in their prime because is more efficient. For several reasons:
A) Is easier. To be a Catholic you have to go through a series of rituals: be baptized,do a first communion, christened.... To be a Muslim you just have to become a Muslim.
B) Internet changed everything making Radical Islam a cancer that spreads easily. Look at those crazy lunatics having their videos of beheading human beings showed at newspapers, magazines (even respectable ones), forums.... the attention they get is in a sick way a stardom. That dude with Brit accent that is cutting people's throat in that village he lives, in that world, is a star.
5. Radical Islam is a disease that needs to be stopped. IMO the approach in how to stop is obviously wrong, mostly because US or most European countries invested in the called collision or war against terrorism have no interest to stop it. The answer to stop it is, and always was, in Middle East itself, the children, woman and man that live there, not in imposing western views instead of asking them: what you need? What you want? Look at how those woman live and are treated, you can't honestly believe that if they had a choice they wouldn't chose different. I'm not talking religion here, I'm talking way of living and human rights, which any form of radical regime denies it to the population and Islam is no different.
But the different choice and path they would take may not be the one the Western world is imposing or offering. There for all those people have no where to go, no side to pick. In one side you have UK and US trying to get their natural resources and destroying their country and on the other they have crazy radicals that transformed their peaceful religion into a system made to hate everyone and destroy all non believers. It's obvious that destroying the country is just a way to propagate hate and create new terrorists, like was said when you see your family die, friends, everything is taken away, what's left? You become a easy target for Islam Fascism.
My grandfather is a great and awarded journalist and he said to me a couple times that the real "woman revolution" didn't happen yet, that feminism as it most pure, genuine form will be a Middle East female revolution. He always say " I probably wont be alive to see it, but you will and don't miss it because it's going to a show, an amazing show. " I hope his right and I hope happens sooner than later, because look at those people, they don't even have a side to chose, one is Western trying to win over their misery and the other is Radical Islam-Fascism also trying to win over their misery.