In a perfect world, the best people would work for the greatest leaders and enjoy optimal conditions. But if your definition of "greatest" involves genius and wild ambition, then the working conditions may be horrible. Some of the most brilliant, creative entrepreneurs have subjected employees to humiliation and driven them to exhaustion for the sake of their world-changing visions. Often, employees have been OK with that.

In his new book Leaders: Myth and Reality, General Stanley McChrystal poses this provocative question: "If leadership is so dependent on people, why are we so energized by leaders who prioritize their mission over their people?" McChrystal, who led the Joint Special Operations Command in Iraq and was top commander of U.S. forces in Afghanistan, approaches this topic through case studies of Walt Disney and Coco Chanel, two trailblazing founders who created heavenly products while putting employees through hell.

Disney refused to share credit, was often ornery and unsociable, and was aggressive with criticism while withholding of praise. Chanel made nasty remarks about workers' appearance, forced models to stand for hours, and required everyone to operate on Coco time. (The book addresses other tensions of leadership through 13 case studies ranging from Robespierre to Margaret Thatcher.)

Yet both Disney and Chanel attracted employees who were the best in their fields. In an interview, McChrystal explained that "there is something in all of us that just wants to be part of something special." People value the esteem of outsiders, who admire the innovation or craft of their employer, he says. More important, they want to be on a top-notch team doing work unmatched in quality and ambition. "Coco Chanel was very difficult to work with, but if you were on her team you were playing for the New York Yankees of fashion," McChrystal says. "These leaders can be a net negative in every way except that they have created something special."

McChrystal compares employees' willingness to sacrifice their happiness--and even their health--to the attitudes of members of elite military units. "The discipline may be tighter. The work may be harder. The danger may be more intense," he says. "And you say, well, why would someone do that?"

His answer: When it comes to the most brilliant leaders doing groundbreaking work, people don't perform a cost-benefit analysis on their decisions to stick. "It is almost a spiritual feeling they get from certain leaders and causes," McChrystal says.

Leader as teacher

Some people follow leaders they can learn from, even if those lessons come at a price. McChrystal cites as examples judges' clerks, aides to generals, and White House staffers. Such people put in insane hours under intense pressure not to burnish their resumes but for the opportunity to observe top-notch talent operating at the epicenter of things. "They go in saying, 'I'm going to do this for a limited time because I'm going to come out so prepared for other things,'" he says. "You can work for a terrible leader and learn a ton if you just sort of tolerate the leadership part."

McChrystal says most leaders who believe they're extraordinary enough to inspire cult-like devotion probably aren't. But even those who are in a position to get away with inconsiderate behavior should resist. He acknowledges that in any organization, particularly scaling companies, there will be periods that require intense work, where the potential for abuse is great. "Leaders smell success, and it can get kind of brutal if they have to push people extraordinarily hard," he says. "But on the other side they have to come back to a more rational place."

At an earlier time in his life, McChrystal says, he was willing to rationalize pushing people to the brink in the name of an important cause. "Now," he says, "I think the organization exists for the people."

McChrystal quotes the leader of a counterterrorism force for whom he worked in the '90s: "Your importance to the mission is not determined by your proximity to the objective." What that means, he explains, is that commandos who go out on a mission do so on the backs of procurement, logistics, HR, and many other functions. Good leaders, he says, point constantly to the contributions that all employees--even at the lowest levels--make to the organization and, by extension, to the leader's success.

Followers are complex

In the end, McChrystal comes back to the followers, people who remain extraordinarily loyal to leaders who are abusive to them. He mentions the enduring popularity of Robert E. Lee with his troops, despite the fact that "if you worked for him in '62 or '63 the chances of you becoming a casualty were freakishly high.

"Once people connect with a leader they are willing to discount the weaknesses and flaws," McChrystal says. "What happens between leaders and followers is not completely rational."