First Blood is a 1982 American action adventure film directed by Ted Kotcheff. It is co-written by and starring Sylvester Stallone as John Rambo, a troubled and misunderstood Vietnam veteran who must rely on his combat and survival senses against the abusive law enforcement of a small town. It is based on David Morrell's 1972 novel of the same name and is the first installment of the Rambo series. Brian Dennehy and Richard Crenna also appear in supporting roles. Wikipedia
Rambo: I could have killed 'em all, I could kill you. In town you're the law, out here it's me. Don't push it. Don't push it or I'll give you a war you won't believe. Let it go. Let it go.