It really isn't that clear, though.
But anyway. As best as I can answer the question, I don't really think that terrorists give a toss one way or the other whether or not the West is obsessed with PC. I don't think that cries of racism have abetted anything (although they aren't necessarily helpful in themselves all of the time). One might even argue the other way: where targets of terrorism were specific, they are often decidedly non-PC, as in the Charlie Hebdo offices. (To be clear, I am categorically *not* blaming the Charlie Hebdo victims for what happened to them.)
So, no. I don't think that "Political Correctness" has anything to do with it. I might wonder what exactly leads anyone to think that a world in which we are less trusting, more disrespectful and more discriminatory would somehow be a safer place. Would the people determined to blow us up start then to think, "oh dear they hate us, I'm not messing with that lot"? Wouldn't that provide yet more motivation?
PC in its satirical form ("Oh hello Mr Blind Person, sorry, I mean visually challenged, how nice to see you -- OH NOOOOOOO I'm SO SORRY!") helps no-one and nothing, to be sure. But that isn't "real" PC, really. And, in the end, if people are determined to kill other people as often, and as horribly, as possible then they'll find the excuse for it no matter what we do or how we behave.