Paul Szoldra/Business Insider
It's a lesson Mattis learned over more than 40 years of leading troops, which culminated in his last assignment as the commander of U.S. Central Command. The four-star general, currently writing a book on leadership and strategy, offered guidance on Wednesday in a talk with business students at Stanford University, where he serves as a visiting fellow.
Business Insider attended his lecture, and pulled out the key takeaways leaders can use.
Be passionate about your role to inspire your workers
If you want to motivate your subordinates, Mattis says you need to be personally motivated, and be passionate about your work. "They may not reach your level, but that's certainly what you're coaching to try and do," he said.
With workers feeding off a leaders' passion and belief in the mission, they will also tend to let mistakes made by a leader slide, as the general found out firsthand.
"[In Iraq] I managed to get my battalion surrounded in the open, flat desert," Mattis said, noting that he was very tired and should have spotted the danger. His men pulled him out of the mess, but they weren't angry - they jokingly asked, "you were just testing us, right?"
Back up your subordinates when they make mistakes
Earning the trust of those you lead is important, and stressing mistakes as an employee learning opportunity - as opposed to something that needs to be punished - can work wonders.
On getting his battalion in a jam, Mattis recalled his own superior officer only saying, "Did you learn anything today?" He knew I learned something, and he didn't need to tell me how stupid I was, Mattis told the audience.
As a leader, Mattis said, you should tell subordinates they just need to focus on their job, and say "I will take the stress that's coming down on your shoulders, you let me have that."
On the flip side, a bad leader who reacts poorly to subordinate mistakes can be toxic. "You want to really pollute your system, you start promoting people that act like little tyrants to workers."
Empower your people by delegating responsibility
Mattis made a powerful argument for the importance of delegation, by drawing upon the British Navy during the 18th and 19th century. It was long considered the best navy in the world at the time under Admiral Horatio Nelson, but as Mattis explained, over the following years it became entrenched in strict regulations, and promoted officers based on how fast they could follow orders, rather than if they could think critically under fire.
The changes did not serve the British Navy well early in World War I, when it was bested by Germany at the Battle of Coronel. Mattis said officers having "no responsibility for taking initiative" was a big reason.
Officers were entirely dependent on higher leadership to tell them exactly what to do. "Many big companies, by the way, have this problem."
Ideally, you want to delegate to the lowest capable level to get the job done, and reward risk-takers, he said.
Get the corporate culture right
There are many challenges organizations can overcome, but having a bad culture is not one of them, Mattis argued.
"You can overcome wrong technology. Your people have the initiative, they see the problem, no big deal … you can't overcome bad culture. You've gotta change whoever is in charge."
Culture starts at the top, and a good or a bad leader sets the tone for how the organization does business.
"[Culture] is whatever the seniors say it is," Mattis said. "That's what it comes down to."