"Klaatu barada nikto!"

One of the best science fiction movies ever made. It was released in 1951, directed by Robert Wise, and written by Edmund H. North, based on Harry Bates' story "Farewell to the Master". Leo Tover was the cinematographer, and Bernard Herrmann provided the musical score. It starred Michael Rennie as the alien Klaatu, Patricia Neal, Hugh Marlowe, Sam Jaffe, Billy Gray, Frances Bavier, and Lock Martin as the robot Gort.

After a flying saucer lands in Washington, D.C., panicked troops shoot Klaatu, the alien who emerges. But a big, scary robot named Gort shows up, disarms the soldiers, and saves Klaatu, who explains that he is on a mission of peace and goodwill. However, he warns that, though his people don't care how many wars Earth's nations wage on each other, if Earth's violence ever extends into space, the planet will be destroyed. Klaatu is taken to a hospital to recover, but distrusting the motives of the government, he escapes and moves into a boarding house, in order to get to know Earth's people better. Will Klaatu be able to return to his ship? More importantly, will mankind be able to control its warlike instincts and preserve itself?

In a decade dominated by paranoid visions of aliens (or Communists or scientists or whatever), "The Day the Earth Stood Still" made a case for abandoning ideological rivalries and living together in peace and understanding. This was, perhaps, a radical idea for the times, but at the height of the Cold War, it was an important counterpoint to the Atomic Age's obsessions with weaponry, annihilation, and dominance. And it left the most important point unspoken: even without Klaatu's ultimatum and robot army, we faced the same choice he offered -- world peace or nuclear war, trust or paranoia, global friendship or global destruction...

"Your choice is simple. Join us and live in peace, or pursue your present course and face obliteration. We shall be waiting for your answer. The decision rests with you."