William McRaven: inspired by John Wayne. (J. Scott Applewhite/AP)

But we read the memo a little more closely, and realized the initial news reports downplayed a few interesting tidbits. First, McRaven revealed the unlikely inspiration behind his own career choice: a John Wayne flick.

The admiral was making the point that he’s not opposed to all pop-culture portrayals of military operations. “Personally,” he writes, “I was motivated to join special operations after watching the movie ‘The Green Berets’, starring John Wayne.”

Just imagine how different things might have been if he’d been similarly inspired, say, by “2001: A Space Odyssey,” which debuted the same year as “The Green Berets.” Would he be an astronaut?

“To this day my Army brethren still wonder where I went wrong,” McRaven writes. (McRaven is a Navy SEAL, while the Green Berets are Army Special Forces — so he only followed his inspiration to a point.)

And with a subtlety his fictional mentor might envy, McRaven also used the message to take a veiled slap at the anti-Obama organizations formed by Special Forces members and veterans. Groups such as Special Operations OPSEC Education Fund have blasted Obama for politicizing the bin Laden raid.

McRaven noted that the military was nonpartisan and serves the president — no matter the party. “By attaching a Special Operations moniker or a unit or service name to a political agenda, those individuals have now violated the most basic of our military principle,” he writes.

Clearly, he wishes special forces would take a cue from another entry in the John Wayne oeuvre: “The Quiet Man.”