Book Review | On Character: Choices That Define a Life
INTRODUCTION
When Stanley McChrystal commanded my battalion and later our regiment, he set a standard of discipline, focus, training, and leadership that shaped my early years as an officer. Like many who served under him, I felt anger and disappointment when his public career seemed to end abruptly in 2010. Yet the years that followed revealed something more enduring than position or power. McChrystal’s steadiness, humility, and intellect remained intact, and even strengthened by his reputation and example he set. His latest book, On Character: Choices That Define a Life (New York: Penguin Press, 2025. ISBN 978-0-593-655-120), feels like the culmination of that long process of reflection.
BACKGROUND
The project began as private essays written to clarify his own thinking, but the result reads as a public meditation on what it means to live with integrity in a restless age. McChrystal presents a simple formula. Character = Convictions × Discipline. But that formula is anything but simplistic and as the book goes on, it feels incomplete. He argues that convictions are the deeply held beliefs that give direction to one’s life, while discipline is the daily act of living according to them. When united, they form character, which he calls “the only metric that matters.” The book is not a memoir (though his personal stories are key) or a manual. It is closer to a modern Meditations as a collection of concise reflections that challenge the reader to measure belief against behavior.
REVIEW
It is difficult to read On Character without recalling the ancient Stoics whom McChrystal frequently cites. Like Marcus Aurelius, he writes not to impress but to remind himself what right conduct requires. His voice is quiet, but ultimately his challenge is not. He asks whether our actions reflect the principles we claim to hold, if we can be circumspect and disciplined in testing those convictions, and whether we have the courage to live by them when the cost is high. For readers of Small Wars Journal, this is not an abstract question. As a journal that speaks both from and to practitioners of irregular warfare, strategy, and the human dimensions of war and conflict, it is one that reaches to the heart of service and command, where the burdens of leadership are moral before they are strategic.
McChrystal’s formula, “Character = Convictions × Discipline,” appears deceptively simple. It offers the neat precision of an equation, but its implications are morally unsettling. If convictions are the deeply held beliefs that drive human action, and discipline is the consistency with which one acts upon them, then the formula suggests that anyone who believes deeply and acts with rigor possesses character. By this framework, a terrorist who acts with unwavering devotion to a destructive cause might exhibit more “character” than a well-intentioned but undisciplined citizen. It is a jarring notion, and McChrystal does not shy away from it. Instead, he invites the reader to confront it.
This is where the book’s challenge begins. The equation forces an uncomfortable introspection, not about who is good or evil, but about who is consistent and who is not. Importantly though, McChrystal argues that true character requires something more than belief and action alone. It demands that convictions be “pressure-tested” through reflection, experience, and circumspection. The disciplined pursuit of false or unexamined beliefs leads not to virtue but to fanaticism. For McChrystal, character therefore becomes a moral crucible forged by the constant tension between conviction and humility.
McChrystal’s formula captures a central paradox of the profession of arms. The same qualities that enable courage, loyalty, and sacrifice can also sustain cruelty, fanaticism, and self-deception. The difference lies not in conviction or discipline alone, but in the willingness to subject both to reflection. It is a challenge to look inward and outward with equal honesty. McChrystal calls this moral posture that resists both self-righteousness and complacency “circumspection.” In this sense, On Character is not a celebration of integrity as a fixed trait but an invitation to ongoing moral work. It may even have the great benefit of developing what another famous retired General (H.R. McMaster) called, “strategic empathy” or the ability to understand adversaries without mirror imaging.
Across his essays, McChrystal returns to a few consistent themes: the primacy of character over reputation, the unity of conviction and discipline, and the necessity of reflection in leadership. He revisits familiar terrain from Leaders and Risk, but with a quieter intensity. Where those books examined how organizations and teams function, On Character explores how individuals must govern themselves. The reflections are brief and invite the reader to pause rather than rush ahead. It is the kind of book that can be read one essay at a time, at night or during a morning commute, and still leave a residue of thoughtfulness that lasts throughout the day.
RECOMENDATION
For those in the profession of arms or public service, McChrystal’s reflections are a mirror more than a map. They do not tell the reader what to do but rather ask who they are, and whether their daily actions align with their deepest convictions. In that sense, the book fits naturally within the ethos of Small Wars Journal: it calls for disciplined thought about the moral dimensions of irregular warfare, where decisions are rarely clear and the consequences are always human.
The book’s great strength lies in its consistency of tone and its clarity of purpose. McChrystal writes with the economy of a soldier and the care of a teacher. The prose is accessible yet meditative, with each short essay offering a distinct lens through which to examine conviction, humility, or discipline. The cumulative effect is powerful but incremental. One can return to a single section and find something new each time. It is a book meant not just to be read, but to be lived with.
Yet the book’s restraint also exposes its limits. McChrystal seldom addresses examples of bad character or moral failure except his own, perhaps intentionally. The reader senses an unspoken foils throughout, but McChrystal never names them. Instead, McChrystal speaks in generalities about the absence of character being glaringly evident in our culture. He seems intent on writing a book that endures beyond the contemporary moment. One that can be read without partisan baggage. Still, that restraint leaves the darker half of the moral spectrum underexplored. The book tells us much about virtue but little about vice, and sometimes the study of one sharpens understanding of the other.
For readers of Small Wars Journal, this omission may be both a limitation and a challenge. The world of disciplined conviction and circumspect reflection that McChrystal describes is not the world we always inhabit. The practitioners who read this journal grapple daily with ethical gray zones: when does conviction justify deception? When does discipline cross into rigidity? Is it acceptable to employ disinformation in service of policy? When is a cause legitimate enough to merit violence, and who decides? These are not theoretical questions. They shape decisions on the battlefield, in policy rooms, and in the information space. McChrystal does not provide answers, but he frames the questions in a way that forces the reader to hold the mirror closer.
CONCLUSION
In the end, On Character is a quiet but enduring companion. Its brevity invites return, its simplicity rewards reflection, and its moral seriousness reminds the reader that leadership demands a life of deliberate thought. It is a book to be revisited as one’s own convictions evolve, and as the demands of service test the discipline to live by them.
When my son left for his first year at a service academy, he was allowed to take only two personal books. I gave him my weathered copy of Marcus Aurelius’s Meditations and my review copy of McChrystal’s On Character. One ancient, one modern. Both written by men who wrestled with the burden of command and the pursuit of integrity. I told him that if he could live the questions those two books ask, he would have done well. For those of us who continue to lead, teach, or serve in the irregular realm, McChrystal’s reflections offer the same quiet challenge: to match our convictions with discipline, our discipline with humility, and our actions with the character we claim to uphold.
