They’re the nation’s quietest killers, known as SEALs because of their delicate work by Sea, Air or Land. But they can also just crash through doors and “double tap” the enemy’s face, as they did with Osama bin Laden this week, killing the ringleader of the September 11th attacks with two point-blank shots. The SEALs were already a semi-legendary unit, the home to gung-ho soldiers who claim to drink snake venom and punctuate their kills with a kiss on the cheek (to take just two examples from the memoirs of former SEALs). Perhaps such braggadocio is inevitable given what it takes to qualify.

SEAL training is two years—the same as astronaut training—and it includes an agonizing combination of brain and brawn work, topped with five days of simulated battle stress. The men call it “Hell Week,” a regime of bullets, bombs, and extreme endurance tests. Men can ring a bell to quit at any time, and two out of three do so. Right now there are only about 2,500 SEALs on active duty in a range of missions worldwide, virtually all of them secret. The best of those are invited to join SEAL Team Six, as it’s popularly known—the team that picked off three Somali pirates from 100 yards on rough seas. And the team that finally got bin Laden.