Thermopylae

Not long ago I finished reading Thermopylae by Paul Cartledge. The subtitle is The Battle that Changed the World. When our local library gets a new book of history I try to get it read in hopes that it will encourage them to expand their non-fiction selections. Cartledge describes the battle between the Spartans and Persia under Xerxes. I haven't seen the movie 300, but it is the battle on which the movie is based.

What I found interesting was in the description of the Spartans as being extremely religious, not something I would have thought about before. Cartledge describes how the Spartans sacrificed animals to examine the entrails to see what the gods were telling them and how they consulted oracles. During the events leading up to the battle, Cartledge describes the many times Sparta's leaders made their decisions based primarily on religous reasons rather than political or strategic factors. I am certainly no expert on Greek history but this did get me to thinking and some questions came to mind.
Do societies with a strong military need to bolster that with religious beliefs? Does the militarism grow out of the religious beliefs, or are the religous beliefs used as a tool to bolster the militarism?
From my perspective the U.S. is a militaristic society. The country spends more on its military than the next several countries combined. Depending on how it is figured, at least half of the national budget is devoted to the military. So the next question I have been thinking about is how religion has been manipulated so that today it seems most evangelical Christians in the US are strong supports of the military and the current wars in Afghanistan and Iraq. Do they just assume like the Spartans did that the gods want us to go to war, or to continue fighting, and since god is on their side the U.S. will "win." The other part of this is to see how the evangelical church has been corrupted. How it has discarded the Jesus of the Sermon on the Mount for a militaristic conquering hero. Or to go back to the Spartans, how all the gods and goddess were portrayed wearing military equipment, even Aphrodite.