To be honest it started long before the Spartans, but the only place I have seen military service as a requirement for citizenship (other than for slaves/ruled peoples) is the movie. With the Spartans military service for males was not a requirement for citizenship really as it was compulsory and everyone was a citizen. Actually the Spartan system was fantastic, force everyone to become a soldier, live in barracks and so on. Make your society like one huge army (though obviously not everyone would be a 'soldier', there would be artisans, tradesmen and so on). Then you try to control reproduction, once you can control the basic instinct, the urge to mate, you can control the rest according to Orwell and I think the Spartans were working on it. Anyhow, back to the topic...

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There's no honorable way to kill, no gentle way to destroy. There is nothing good in war. Except its ending.