Former aides wonder: Did Petraeus stumble in unfamiliar terrain? No general in the U.S. military had a more loyal retinue of staff officers than retired general David H. Petraeus. Many of these soldiers had followed him through multiple tours in Iraq and Afghanistan over the past decade. The collapse of his storied career after his admission of an affair has left them all asking the same questions: How could the illicit relationship have happened? And how does it square with the officer they knew and admired? In some cases, the first question is asked literally. In Afghanistan, it would have been nearly impossible to conduct an affair out of their view. Petraeus had a small office in the cramped NATO headquarters and slept in a tiny trailer set amid the living quarters of his staff officers. Indeed, the former general has told those close to him that, although he was close with his biographer, Paula Broadwell, in Afghanistan, he did not begin the affair with her until after he left the military last year. But for many of Petraeus's former staff officers, the bigger question is how a general who preached the importance of self-discipline and integrity, who almost never seemed to lose control of his emotions during a decade of almost nonstop stress and combat, stumbled so badly in his personal and professional life. "I am really shocked by it because it is so different from the Petraeus I knew over the course of three tours of Iraq," said one Army officer who was part of Petraeus's inner circle and who asked for anonymity so he could speak candidly. We've all been e-mailing back and forth. This is the last thing in the world we would imagine. He did a lot of good for the country and a lot of good for us. Since his first combat tour in Iraq in 2003, Petraeus had cultivated a cadre of a few dozen loyal staff officers, many of whom had doctoral degrees from top universities and taught at the U.S. Military Academy at West Point. Usually, he personally selected these men and women to serve on his staff. In Afghanistan, the retinue grew as people drawn to his fame and eager to launch their own careers took up positions for him in Kabul. "He didn't seek out these people, but he also didn't turn them away," said an officer who spent 40 months working for Petraeus in Iraq and Afghanistan. Prominent members of conservative, Washington-based defense think tanks were given permanent office space at his headquarters and access to military aircraft to tour the battlefield. They provided advice to field commanders that sometimes conflicted with orders the commanders were getting from their immediate bosses. Some of Petraeus's staff officers said he and the American mission in Afghanistan benefited from the broader array of viewpoints, but others complained that the outsiders were a distraction, the price of his growing fame. Broadwell, who first met Petraeus when she was a doctoral student at Harvard, was treated as though she were a member of Petraeus's inner circle and was afforded VIP housing at the main U.S.-NATO headquarters in Kabul.