I've been pondering a parallel line of reasoning a lot lately: That the decline in religious belief explains much of the opposition to war, especially on the Left. It may seem counter-intuitive, but once you dig down, if large swathes of the population do not believe we have immortal souls (I myself am agnostic on the subject) that will be rewarded for a virtuous life, then the perceived cost of every individual life in a war is magnified to a much greater level than was the case in previous wars (fought by societies with a broader cultural acceptance of the idea).

I say perceived cost because, of course, the actual cost is the same for that individual. His soul either moves on to the afterlife or does not. But a life that is extinguished forever will be seen by those who remain as a much greater sacrifice than one that has merely transitioned to eternity. So, as the Left has moved toward largely abandonning religious belief, the intensity with which they oppose war-making in general has risen.

That intensity is somewhat ameliorated in cases where said war-making is performed by Democrats, of course, because, of course, the intentions (and, as we all know, in the absence of any over-riding standard of morality, all that matters are what one intended; actual results are ir-relevant) of a Democrat warmonger will necessarily be good ones. This is in marked contrast to the automatically suspect, nasty, evil, self-aggrandizing, morally reprehensible motivations of any Republican.

Belief in an afterlife may help you face death, but judging by the religiosity prevalent in prisons, it doesn't do much to improve your behavior in this life.