Most wars which have taken place in the Western world in the last few centuries have been about politics, land and power and not about religion.
Depends on who is talking and who is being asked. While I agree that almost all wars reduce to land grab or some other natural resource, that motive is mostly reserved to the monarch, aristocrats, or plutocratic elite. Religion is the glue used for the commoner. Certainly Sun Tzu thought so when he wrote about the importance of convincing your soldiers that they had a moral cause and that religion aided with this. Point being, you ask the grunts why they are fighting what their cause is, and you'll always get some moralistic response, but I think after a couple dozen centuries of documented history we should know better by now.
Religion does deserve credit for war though. It's not off the hook if it happened a long time ago. Those events have shaped the world as it is today. Such dismissal is foolish. If one religious galvanization breeds resentment of those who you conquer and gives rise to whole new religions hell bent on returning the favor. I acknowledge the motive of war is economics, but religion still acts as the prime means to manipulate people into waging it for the benefit of an elite few.
To say modern Christianity and modern Christians have nothing to do with the wars being fought right now is naive.