Rambo: First Blood Part 2 (which for simplicity in this post will be referred to only as Rambo, not to be mistaken for the fourth installment of the First Blood series) presents a re-writing of the Vietnam war. Made in the mid-1980's amidst the reexamination of America's treatment of Vietnam veterans, the film offers not only a way to redeem the American public for its poor reception of returning soldiers, but a way to win the war itself. Rambo's mission is to find American POW's still in captivity in the jungles of Vietnam. His success in rescuing several such soldiers not only presents filmgoers with an American victory in Vietnam, but shows forgotten and mistreated vets being brought back into the fold.
Key to the film's rectification of history is the transfer of all responsibility for the war onto a single, un-American source. While America's culpability for the treatment of its veterans is embodied by Murdock, the bureaucrat in charge of the ersatz rescue operation, and while Rambo kills a fair share of Vietnamese enemies, the real power behind the POW camp is the Soviet Union, in 1985 still a hot adversary to the United States in the Cold War. In this way, present and past animosities are united and blame is simplified onto a single, sneering, Soviet bad guy, sparing the audience any need to consider a more complex reality.
Other similarities strengthen the connection between the two films. Rambo and Jake are both injured Marines — Jake's injuries are physical and visible, while Rambo's pain is emotional and mental — recruited to help in missions that will give them a "second chance." For Rambo, the mission is an opportunity to be released from prison and to finally get to "win" a war. For Jake, a tour on Pandora is a chance to leave the bleakness of an environmentally ravaged Earth and possibly have his injured legs repaired. Both heroes are sent to fulfill the orders of a military or corporate "machine" (both of which are headquartered in military-style bases carved out of and fenced off from the surrounding jungle), but each redefines his mission according to his conscience, putting him at odds with his own society. Rambo, like the Na'vi, is more at one with the natural environment than are his adversaries. He hides from enemies by covering himself in mud or by lurking underwater. He uses nature as a weapon, making traps and weapons out of tree roots and vines. Both the Na'vi and Rambo use simple weapons like bows and arrows and knives against the high-tech weaponry of their enemies (there is at least one instance of rack focus between shooter and arrowhead in each film!). Rambo repeatedly shows his disdain for technology by cutting loose his gear, shooting up a control room, and declaring "I've always believed that the mind is the best weapon." (Rambo is adept, however, at flying military helicopters, which are emphasized in both films as an important way of travelling between the two worlds straddled by the heroes). And it is probably not insignificant that Avatar writer/director James Cameron also co-wrote the screenplay to Rambo.