“He would put this mask on, but behind it was a shattered version of the man I knew,” said his wife, Susan Ullman. She begged him to get help, but he refused, telling her: “I’ll lose my security clearance. I’ll get thrown out.” When she quietly reached out to his superior officers for guidance, she said, she was told: “Keep it in the family. Deal with it.”

And so he did. Last summer, just days after his 36th birthday, Sergeant Lube put on his Green Beret uniform and scribbled a note, saying, “I’m so goddamn tired of holding it together.” Then he placed a gun to his head and pulled the trigger.

To a growing number of medical experts and the Special Operations Command itself, suicides by soldiers like Sergeant Lube tell a troubling story about the toll of war on the nation’s elite troops. For 12 long years, those forces, working mostly in secret, carried the burden of much front-line combat, deploying time and again to the most violent sectors of Iraq and Afghanistan.