Truth is if religion didn't exist, we'd fight wars in the name of race or tribe or political belief or whatever. In Gulliver's Travels they fought a war over whether to eat your eggs from the pointy end or the rounded end once you put them in an egg cup. Some religions forbid war including Buddhism and Christianity (I say unto you resist not evil, turn the other cheek, says Jesus in Matthew 5).
Oh and by the way "turn the other cheek" does not mean staying in a chronically abusive relationship (that is a different issue but is, obviously, wrong and always wrong).
But what is the point in defending religion whilst God watches the religious amongst us kill, wound, and hurt one another, and weeps at what we do to one another? Religious leaders have a great deal to answer for. I once attended an audience with the Dalai Lama (me and a thousand others so it wasn't that exclusive) and he laughed as he held out his right arm and said, "This hand is made for hugging, not hitting". But when did you last hear one of our religious leaders say the same thing so emphatically? If they do they couch their words in mumbling qualifications, as the then Archbishop of Canterbury who said at the time of the Falklands, "War is wrong but there are times when we must stand up and be counted . . . " And am I any better? If Hitler walked in Europe today would I not be in the vanguard to kill him and his? Luther King lived by the maxim, defend others but never defend yourself. But that's a compromise. Jesus' take on war is an absolute prohibition.
But the underlying point is, say you saw some bully beating some wimp into a pulp for spilling his pint. You'd defend the wimp. But would you beat the bully into a pulp in turn? Nope. If he does it again you'd interfere again. But you wouldn't cripple, dismember or kill him in turn. We have a responsibility to protect everywhere from Afghanistan to Iraq. But not to stay there to interfere. There is a fine line between peace keeping and invasion.
In today's Britain we spend billions on Trident. We (little Britain) have enough nuclear force to wipe out half the known world. Two billion pounds is enough to keep a million man army paying them twenty k each. What a peace keeping force. Send them to Syria instead of squandering the money on nuclear submarines. We have our priorities quite wrong.