A Chequer-Board of Nights and Days

You wrote:

"The aliens are irrational because they're all crazy religious freaks!  This implausible solution has been adopted wholesale by Mr. Scalzi. "

Hmmm... I see where you are coming from, although I don't know that I agree with it.

Primarily, I would disagree that the aliens seen as religious are either crazy or freaks (or irrational). Two alien races are seen as being influenced by religion in the book: The Consu and the Rraey. The Consu are definitely not crazy nor are they freaks -- they are somewhat incomprehensible, but that's a factor of being so much more advanced (technologically and otherwise) that their motives are difficult for humans to parse. I would say their religion is incomprehensible to the humans, but I think that's in large part because the humans have not gone out of their way to try to understand it (for example, the humans see the opening battle prayer as something akin to the national anthem -- i.e., a per forma ritual -- when it's rather more significant than that).

Remember that as a matter of narration, we're seeing things from the point of view of John Perry, who is not an omniscient narrator; he's seeing the Consu initially as the human government in the story sees them. I tried to make it clear Perry recognizes that the Consu attach a deeper symbolism to battles than CDF intelligence does. The Consu certainly are guided by religion, but despite the humans' inability to figure out the teleology, there's not a suggestion that the religion itself is irrational or freakish.

The second race seen motivated by religious factors is the Rraey, who launch the attack on Coral in order to obtain resources important to their religious practices. Certainly from the human point of view this is not a good reason, and the humans themselves are dismissive of the Rraey, and the technological constraints they see Rraey religion placing on technological/social development. But again, the POV is from John Perry, who is not in a position to know all the details of the Rraey religion, and who gets his information from the human database of information, which may or may not be entirely reliable.

I don't think it's inappropriate to show alien cultures influenced by their religions, as among other things our cultures so clearly are. I also don't think it's inappropriate to show humans having biases or misunderstandings of the religions and cultures of those they fight, since (again) that's something that's not unknown here in reality. I do agree that in the narration the aliens are seen as incomprehensible and irrational, but the question to ask is: Is that because they are (and, additionally, that it is due to their religion), or because the humans in the story are working from bad premises?  Are the humans in the book taking seriously the tenets of faith of those whom they fight against?

I have my own personal opinion on the matter, of course. Yours may (or may not) vary from this. There's a lot that's left ambiguous in the text partly so I could expand on it in future books (and partly because the book has to end sometime) but also because I think it has the potential to engender discussion and debate (like this).

I will say this: There's a character in the OMW sequel The Ghost Brigades who is both alien and religious; I also think he's the most morally-engaged person in the story, and his moral point of view ends up being -- in my opinion -- the heart of the story.

-- John Scalzi