2) With all due respect, the Crusades cannot be separated from the current "War on Terrorism", because the enemy of Western Civilisation is the same mohammedans.
The reason I suggest a focus on the medieval timeframe is because it is very easy to fill the thread with contemporary references, and there is no shortage of such threads.
But if you insist, it is my opinion that the present unpleasantness is fundamentally different from the Crusades. The leaders of the War on Terror are very specific in shunning a Christians Against the Islam designation; Jerusalem is not the stated objective; there is no popular upswell of support comparable to one that fueled the Crusades.
"the enemy of Western Civilisation is the same mohammedans."
Except that since then, Western Civilization has donned the black hat. Back then, Western Civilization did not stand for cutting heads off babies, sodomy, pornography, contraception, fornication and adultery. It is not for nothing that the Pope calls this the Culture of Death.