[M]ost people will guess "A ketchup genius?" Wargamers will be ones who answer: "The German general who invented modern tank warfare, and who wrote a famous memoir, Panzer Leader."
That's from a very interesting article on the intersection of geek culture and all matters military. I think, in addition, that geeks are drawn to situations where the gloves come off, the normally Byzantine rules of society (that geeks are notorious for barely understanding) are cast by the wayside, and the geeks can finally flex their full mental muscles in an ultimate test of mind, will, and body. Sometimes that means war, but it also shows up a lot in survival fiction.