It was necessary to maintain the illusion for your crew.
3 seconds sound clip from the The Hunt for Red October movie soundboard.
You can hear this line at 01:54:06.926 in the Blu-ray version of the movie.
Quote context
[...]
- Well, the captain seems to think you're some sort of cowboy.
(In Russian) You talk Russian. -A little. It's good to know what the enemy thinks, isn't it? -It is.
- What gives you the right to fire on my ship?
- Your signal said nothing of a torpedo.
- It was necessary to maintain the illusion for your crew.
- My crew are being rescued, yes?
- Then how did you know our reactor accident was false?
- Well, that was a guess, but it seemed logical.
- Very well. I present you the ballistic missile submarine Red October.
- My officers and I request asylum in the United States of America.
[...]