Recently, I was honored to connect with General David Petraeus to discuss his approach to leadership. His storied career in the military includes leading coalition forces and counterinsurgency efforts in Iraq and Afghanistan; he literally wrote the book on counterinsurgency and is credited with turning around the war in Iraq in 2007. In short, Petraeus knows a thing or two about leadership.

Movies often portray the military as rigidly hierarchical, with generals taking a top-down approach to leadership. It’s a well-known stereotype that Petraeus doesn’t endorse. Instead, he promotes a flatter organization and entrusts soldiers and officers with autonomy to advance the mission.

In the military, this is a necessity: War brings unpredictable situations, so your team needs to be able to think on its feet and take action quickly. But in such a high-stakes environment, how do you effectively relay the mission to the team? And how do you ensure the team takes the “right” actions when faced with uncertainty? That comes down to effective communication of the big ideas – and pivoting an idea when it loses its power.

According to Petraeus, effective leaders don’t dictate the tactics; they establish the mission, the boundaries and the direction. Then they empower the team to determine the best route. “Initiative has to be pursued within the left and right limits established by the strategic big ideas,” says Petraeus. In an interview with Vanity Fair, Petraeus joked that it’s a rare soldier who has served with him and hasn’t been “PowerPointed to within an inch of his life.” Before soldiers take action, Petraeus wants to be sure there’s absolute clarity about the mission.

It’s easy to see the parallels to the private sector (both the use of PowerPoint and the importance of communicating the mission). At Zillow Group, our mission is to build the largest, most-trusted, and vibrant home-related marketplace in the world. Our mission serves as our North Star, and our core values serve as guardrails, empowering employees to make decisions in the face of ambiguity. I don’t make every decision every day; in fact, I spend most of my time simply making sure teams are motivated, equipped and empowered to make decisions themselves. By communicating the mission and then delegating the tactics, our people can move faster.

Petraeus is also a big believer in adapting how he communicates the mission. “I've always tried to get an understanding of what leadership style will bring the best out in each of those who reports to me. For some of us, one pat on the back a year is all that's needed. Others need a bit more reassurance and encouragement, some perhaps even occasionally need a bit of a nudge in the backside,” he says.

Great leaders also understand that, sometimes, big ideas need to evolve. Take AOL: At the height of its success, the company had an opportunity to refine its big idea (dial-up internet access for the masses) as other competitive players (Google) made inroads into the market. Instead, AOL lagged behind in favor of a “bigger, more powerful idea,” says Petraeus.

Juxtapose AOL with Netflix: They blew up their core business – mailing DVDs – because streaming was the way forward. Then they doubled down on original content in direct competition with their content partners who supplied their inventory. Netflix’s willingness to pivot its big ideas is why the company is winning: Netflix now entertains nearly 100 million subscribers worldwide with its binge-worthy content.

Petraeus noted that “great firms have formal processes to constantly ask, ‘What is the iceberg out there? And what do we need to do to adapt, evolve and continue to succeed?’” It’s insufficient to reflect on or change the big idea, cautions Petraeus; you also have to be able to abandon the ones that don’t work. That’s the hard part.

At Zillow Group, we understand there’s power in questioning the status quo because stagnancy is dangerous. We’ve formalized a process that drives innovation through regular Hack Weeks, where teams can work on new products of their choice for the entire week. In fact, we’ve had some of our most successful features and initiatives arise from a week of liberated hacking – a term we use loosely because the week now includes participation from many parts of the company, not just engineering.

We know it’s not enough to recite our mission and print it in big letters on our walls. We have to move fast, think creatively and continuously evolve our big ideas.

It was an honor to speak with General Petraeus. We covered a lot of ground in our conversation, so make sure to listen to the full episode.

You can read a transcript of the interview with General Petraeus, as well as others in the Office Hours series, here. If you like what we’re doing, please write a review on iTunes.