How close did the US come to averting Japan's attack on Pearl Harbor?

"In a small office at Pearl Harbor, overlooking the battleships at the heart of America’s seafaring power, the Commander of the Pacific Fleet tries to figure out how much danger he really faces. His intelligence unit has lost track of Japan’s biggest aircraft carriers, but assumes they are resting in a port far away. The admiral thinks Pearl is too shallow for torpedoes, so he never puts up a barrier. As he frets, a Japanese spy is counting the warships in the harbor and reporting to Tokyo."

-- From the introduction to John Batchelor's riveting interview with author Steve Twomey about Countdown to Pearl Harbor, published November 1, 2016. You will be kept guessing right up to the attack, but in the end there is no definitive answer to the question I posed. And that is the part that haunts, and will continue to haunt the annals of war and American history.

Here is the podcast of the interview.

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