This power you speak of... They must be made to realize that it exists.
6 seconds sound clip from the The Day the Earth Stood Still (1954) classic radio play.
You can hear this line at 00:26:25 in the radio play.
Quote context
[...]
- That is what I came to see you about.
- One thing, Klaatu. Suppose this group should reject your proposals.
- There is no alternative, Professor. In such a case, the planet Earth would have to be eliminated.
- I assure you, such power exists.
- The scientists who are attending these meetings have come here from all over the world.
- This power you speak of... They must be made to realize that it exists.
- Now, you mentioned a demonstration of force, something that would affect the entire planet?
- Perhaps a little demonstration.
- Something dramatic, but not destructive. It's quite an interesting problem.
- Would tomorrow be all right?
- Then tomorrow at noon? Good.
- Going out tonight, Mrs. Benson?
- Oh! Oh, it's you, Mr. Carpenter.
[...]