In this age, I don't care how tactically or operationally brilliant you are: if you cannot create harmony - even vicious harmony - on the battlefield based on trust across service lines, across coalition and national lines, and across civilian/military lines, you need to go home, because your leadership is obsolete.

Trust across the lines

We tend to think of strong leadership as someone who makes the right call and forces everyone to fall in line. But Mattis is describing something harder: the ability to get people who don't naturally trust each other—who may compete for resources, follow different rules, or come from different worlds—to actually work toward the same goal. That takes a different kind of skill entirely.

The phrase "vicious harmony" is striking because it doesn't pretend everyone will like each other or agree on everything. It just means they have to function together despite friction. You see this in any real workplace: the operations team and the creative team don't think alike, the finance department and the engineers speak different languages, yet somehow the project has to move forward. The leader who obsesses over being clever while ignoring these trust gaps usually ends up managing chaos instead of work.

What makes this relevant now is that most important problems—whether in business, health, or communities—require people from different backgrounds and expertise to collaborate. Technical brilliance without the ability to build that trust becomes a liability. You're not wrong about the solution; you're just stuck because nobody follows you across the gap.