can religion be blamed for war?

[binary solo]

Nope, never.

Religion has been used as an excuse for war, and a scapegoat. But war is only ever started for 3 reasons, power, control and resources (land).

There isn't one religion whose teachings advocate starting wars in order to achieve the aims that the religious teachings intend. People have observed that Muhammad said Islam would be spread by the sword. And it's true, he did say that, and it happened. However if you actually read what he said he's actually making a predicition, not a commandment. He didn't tell his followers to go out and pillage all non-Muslim lands and force them to convert to Islam. He just new that the state of the world over the coming centuries meant that Islam would meet with violent opposition necessitating wars to be fought, and I guess he was predicting that the Islamic armies would mostly be victorious and hence they would spread the influence of Islam as a result. That's not to say many Islamic leaders didn't abuse and mis-use Muhammad's prediciton as justification for expansionist wars (in order to gain power, control and resources).

The question you need to ask in order to lay any blame for war on religion is whether you think there would be more, less or about the same amount of war throughout history if there was no religion.

Given the fundamental causes of war have nothing to do with religion (see above), and religious teachings have always advocated peace and tolerance of other people, I'd say it's impossible to rationally claim that a history free from religion would have been a more peaceful history than the one we've got. Ergo religion is not to blame.