Opening this weekend: Rambo: Last Blood—With the obvious exception of Rocky Balboa, troubled Vietnam vet and former POW John Rambo has been Sylvester Stallone’s most enduring character. He debuted in First Blood, the 1982 adaptation of David Morrell’s novel, as a PTSD-afflicted ex-Special Forces drifter who makes some small-town deputies wish they hadn’t messed with him. It was one of Stallone’s more intense and poignant early performances. The 1985 sequel, Rambo: First Blood Part II,...