Rambo is released from prison, is flown to a staging area in Thailand, and is sent into Vietnam to search for American POWs shortly therafter.
Rambo, with the assistance of a local woman, Co Bao, finds American POWs in Vietnam and tries to escape with one. However, during the extraction, Marshall Murdock, in charge of the operation, orders that Rambo be abandoned, and all documentation of POWs be destroyed, much to Colonel Trautman's dismay. Trautman criticizes Murdock for what he had done, but Murdock ignores him.
Rambo is taken into captivity by the Vietnamese soldiers, and is tortured by the Soviet Red Army. With the help of Co, Rambo escapes, nearly destroys the Vietnamese and Soviet armies, and flies back to Thailand with the rescued POWs.
He then threatens Murdock to find the remaining POWs, or Rambo will find him.
In the end, Rambo tells Trautman that hed die for his country and he deeply wants his country to love him as much as he loves it.