John Rambo's former Vietnam superior, Colonel Samuel Trautman, has been assigned to lead a mission to help the Mujahedeen rebels who are fighting the Soviet invasion of Afghanistan, but the Buddhist Rambo turns down Trautman's request that Rambo help out. When the mission goes belly up and Trautman is kidnapped and tortured by Russian Colonel Zaysen, Rambo launches a rescue effort and allies himself with the Mujahedeen rebels and gets their help in trying to rescue Trautman from Zaysen.

Lincoln Hawk (Stallone) is a struggling trucker who arm wrestles on the side to make extra cash while trying to rebuild his life. After the death of his wife, he tries to make amends with his son who he left behind 10 years earlier. Upon their first meeting, his son does not think too highly of him until he enters the World Arm Wrestling Championships in Las Vegas. His hope is to receive the grand prize of $100,000 and an expensive current custom semi-truck and thus start his own trucking...