What if, Siegel asked, a government agency came to him with an encrypted text message from an Apple device that supposedly concerns hijacked airplanes, skyscrapers and dirty bombs. Would Apple give it up the plain text? Would it let the government in the back door?

Not possible, says Cook.

And then he makes the case for strong encryption with a clarity and frankness you don’t often hear in this country when national security is invoked.

COOK: National security always matters, obviously. But the reality is that if you have an open door in your software for the good guys, the bad guys get in there too. Think about what happened here in this city with as many—literally tens of millions of employees of the government getting their data stolen. And so we think that our customers want us to help them keep their data safe. My own view is, everyone’s coming around to… there’s some core tenets, and those core tenets are that encryption is a must in today’s world. And I think everybody’s coming around also to recognizing that any backdoor means a backdoor for bad guys as well as good guys. And so a backdoor is a nonstarter. It means we’re not safe.

SIEGEL: For the U.S. government and other governments as well.

COOK: For any government. I don’t support a backdoor for any government, ever.

It’s a good interview. Just over 8 minutes. Includes questions about Google, Apple’s use of customer data and those rumors about an Apple car.

LINK: Apple CEO Tim Cook: ‘Privacy Is A Fundamental Human Right’

Follow Philip Elmer-DeWitt on Twitter at @philiped. Read his Apple (AAPL) coverage at fortune.com/ped or subscribe via his RSS feed.