Religion and war

Via Arts and Letters Daily and The Spectator:
On the whole, though, for a millennium in which religion has loomed so large, as a motive for actual war it seems to have been rather secondary. What then explains this obstinate modern conviction that religion is the driving cause of organised bloodshed?
Click the link to see more: Religion does not poison everything - everything poisons religion » The Spectator
Points:
  • “…religions are corrupted by success. The more popular they become, the closer they are drawn into the ambit of state power, the more their practice and doctrine have to be remodelled to suit their new overlords.”
  • “This [the idea that religion is the cause of most wars] is the misunderstanding which drives fanatical secularists to demand that faith be driven out of the public square and permanently banned from re-entry, like a drunk from the pub he always picks a fight in.”

It may be the same for ideologies (those belief systems generally ending with –ism), which are built on unprovable presuppositions rather than an unprovable deity. For writers of faith, how can you address that issue?