“There is the perception this was always a ‘kill mission.’ I’ve been around the community 30 years and never have I heard the words ‘kill mission,’ ” says Pfarrer. “The words ‘kill mission’ seem to constitute an unlawful order. We’re not stupid.”

In his book, Pfarrer describes the two types of missions SEALs are generally given: to “interdict” a high-value target or to “neutralize” him.

While the latter essentially amounts to a kill command, the “stated plan” of the bin Laden mission was to “interdict a high-value individual in a non-permissive environment,” he says.

Of the “thousands” of missions that have been conducted by SEALs “the vast majority are capture missions,” Pfarrer says. “If the guy surrenders, he gets captured.”

As an example of a "neutralize" mission, Pfarrer notes the order to kill Musab al-Zarqawi, bin Laden's operational commander in 2006. Mr. Zarqawi was killed after two SEALs hiding nearby used laser pointers to direct a guided bomb to the house where Zarqawi was staying.