Blackberry knew what they were up against but were unable to respond to it fast enough.

Publicly, Mr. Lazaridis and Mr. Balsillie belittled the iPhone and its shortcomings, including its short battery life, weaker security and initial lack of e-mail. That earned them a reputation for being cocky and, eventually, out of touch. “That’s marketing,” Mr. Lazaridis explained. “You position your strengths against their weaknesses.”

Internally, he had a very different message. “If that thing catches on, we’re competing with a Mac, not a Nokia,” he recalled telling his staff.