The Deer Hunter (1978)

When Michael (De Niro) returns home, he finds out that Steven (Savage) is in hospital and Nick (Walken) is still in Vietnam. Nick's trauma of the events of their capture during the war has lead him to continue playing Russian roulette. Michael eventually decides to go looking for him. He finds him in a small slum in Vietnam where they are holding Russian roulette contests. When Michael sees that Nick is a contestant, he tries to talk him out of it, but it doesn't work. Michael decides to play against him, and again tries to talk him out of it, but he realises that the game won't end until one of them is dead. Nick loses. They hold a funeral for Nick and all the people back home mourn him at the dinner table. They all sing 'God Bless America'.