Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Military SF that's heavy on the SF

I'm generally don't read Military SF, not for reasons of political or personal taste, but because I find most Military SF heavy on the Military and light on the SF. I picked up Birmingham's first book, Weapon of Choice, on a whim, and I'm glad I did. Like the other military SF authors on my short list (Eric Flint, for example) Birmingham gets deeper into the thought-provoking ideas that come out of a speculative situation.There's some combat and some fun with high-tech weaponry, but there's also real SF, looking at the culture clash between 2020 and 1940, the effects that prolonged ideological wars might have on our current culture, and the impact of a glimpse of the future on course of the war. He also looks at more military topics like the impact that modern military theories of operations and training might have on WW II, as the high-tech ammo starts to run out.