Unfortunately, it doesn't look like that's the case. I have not seen the film, which opens this weekend, but while I was at the book store the other day, I did look through the "graphic novel" (a high-brow comic book) on which it is based.
A few have recommended the comic book and the film to me on the strength of a few lines about fighting for "reason" and "freedom." Unfortunately, that is not actually what is actually dramatized in the comic book—and based on the review linked to below (and another interesting but overwritten review in the Washington Post) the same is true of the film.
I read a few comic books by Frank Miller back in the 1980s, and his sense of life has not fundamentally changed. On the one hand, he is interested in portraying heroes. On the other hand, he has a deeply malevolent view of the world. In his view, heroes have to sacrifice and suffer in this rotten, corrupt world—and so he positively worships blood and sacrifice, a trend taken to its full extreme in 300.
Given his sense of life, it is fitting that Miller takes the Spartans as his heroes. But the Spartans represented the worst of Greek civilization: a quasi-totalitarian society based on slavery, whose citizens trained for nothing but war, bloodshed, and death and who produced none of the art, science, and government that made Ancient Greece great.
Yes, the story of Leonidas and the 300 at Thermopylae was inspiring (and for reasons that Miller largely misses in his obsession with blood and gore). But I think the real heroes of the Persian Wars were the Athenians—so I'll hold out for a film dedicated to Themistocles and the Battle of Salamis.
"Persian Shrug," Kyle Smith, New York Post, March 9 As 300 doomed warriors of ancient Sparta march into the Battle of Thermopylae against hundreds of thousands of Persians, the movie version of the Frank Miller (“Sin City”) comic book becomes less a salute to the “Braveheart” school of right-wing action movies than a parody of them….
Leonidas…bellows about honor as he begins a decathalon of dishonor. Rampaging in his leather Speedo, he murders wounded enemies, desecrates their remains, insults allies, and confuses death with glory. His troops are like al Qaeda in adult diapers….
Leo frames his struggle as a war against barbarism, but his is a "culture" that puts babies to the sword for looking like weaklings…. Like "no prisoners," which also pops up here, this is a familiar battle cry that makes no sense unless violence is war's goal rather than its means….
But keeping in mind Slate's Mickey Kaus' Hitler Rule—never compare anything to Hitler—it isn't a stretch to imagine Adolf's boys at a "300" screening, heil-fiving each other throughout and then lining up to see it again.