Here's something interesting form A.O. Scott's review of John Carter:
That would be John Carter himself (Taylor Kitsch), a Confederate veteran with a knack for mortal combat and a gloomy aversion to same. But the fight finds him, first in a box canyon on loan from a John Ford picture and then -- nonspoiler alert! -- on Mars. The red planet resembles the Old West both geologically (a lot of dusty red rocks) and thematically.A Civil War rages between two factions of Red Men, though it is actually the green, four-armed humanoids known as Tharks who serve the traditional western function of Indians, Noble Savages trying to fight back against a technologically superior foe. The war between the city-states of Helium and Zodanga is more like something out of "Star Trek," but with elements of the sword-and-sandals epics of the 1950s, what with the togas and the armor, the pillars and the pageantry and the ripely histrionic dialogue.