Strongly held religious convictions to the point of war is a similarity. They are part of the mix in Iraq and in Ireland. I agree that the US does not see this as a religious conquest.
And Cromwell did.
I don't mean to discount your comparison; religion is the subtext in everything that happens in the Middle East. I just don't think the West has the religious critical mass (pardon the pun) to mount a crusade again. And I don't think Islam has the cohesion. So it's a matter of apathy versus chaos.
At least at the religious level ...
Whatever the West is fighting for, it isn't Christianity.