It's not too complicated. Centuries of conflict against the West (with the aggressor role having switched more from the Ottoman Empire to the West) have indeed shaped things, with the past century being very significant to what is happening today. A great deal of strife is due to Western military and corporate ventures. We say the same exact thing throughout Asia and Central and South America during the Cold War as the Stalinists were the biggest ideological threat who were also created largely as a response to Western military and corporate ventures.
And Islam, there is also a very violent history and it does have a primary text that gets rather violent itself. For the same reasons we cannot ignore the religious motives behind the Crusades, we cannot ignore the same in modern Jihadists. Because it can't be overlooked or ignored, as getting into Paradise is the goal of both. And we have to remember, Muslims really are their own worst enemies. They sometimes get so violent and nasty with each other that even some places like Tunisia have banned niqabs and burkas as a step towards combating extremism. And this is them dealing with each other, were one group of Ummah says it will be this way, while the other says it will be this way (basically, the core of the Sunni/Shia schism is over difference in opinion and no one being able to prove themselves right or the other wrong).