The interesting thing about Star Wars (taken in context without sequels) is that there are so many things in that Lucas gives from a military perspective, but there are just as many things he gives you from a fantasy perspective.

Tarkin is pure military, Vader is pure fantasy. The whole empire is really taken from WWII fascist dictatorships (Lucas and Spielberg are huge WWII buffs) Heck the stormtroopers are just like the SS as someone mentioned earlier.

I don't know who was the 'true' villain of Star Wars, but I think that is the brillance of the Original Star Wars: As you get older, and understand miilitary history, you sort of understand the hiearchy of dictators and Tarkin seems like the real bad guy. But as a kid, I was geared to the fantasy end more and I thought Vader was the real bad guy.

For whatever you want to say about Lucas and his later failings in the series, the Original Star Wars has alot of depth to it for a simple fairy tale movie.