On war, Trump must remember the wisdom of St. Augustine

Peace is not merely the absence of fear. It stabilizes the conditions under which ordinary people can act, plan, invest, and raise families.

Chaos, by contrast, is asymmetric. It falls hardest on those least equipped to bear it, displacing populations, destroying fragile livelihoods, and forcing the marginal participant — whether the paycheck-to-paycheck citizen, retail investor, or refugee — into the worst possible outcomes.

This is why the decision to go to war cannot be judged by intention or immediate success alone. On this point, St. Augustine of Hippo remains indispensable. He understood that force must be governed by prudence and ordered toward the restoration of peace, which requires reckoning with second- and third-order effects. The failure to do so in the past is instructive —and the conflict today in Iran is falling into a similar pattern.

Augustine did not romanticize peace. He understood that conflict is a permanent feature of political life after the Fall. But he insisted that the use of force must be governed by prudence, not abstraction. War, if it is to be just, must aim at the restoration of order, not the satisfaction of ideological or psychological impulses.

More pointedly, rulers bear responsibility not only for the justice of their cause, but for the consequences their decisions impose on their own people, and this is where the U.S. Iraq War represents a profound failure.

The case for the war, as it was presented, rested on a mixture of claims: weapons of mass destruction, democratization, regional transformation, credibility. Some of these were empirical claims that proved false. Others were aspirational claims that proved ungrounded.

But even setting aside the question of whether the initial justification was accurate, a more fundamental error was made at the level of prudence. In 2003 the United States chose to dismantle the Iraqi regime without a credible plan for the order that would follow. That is not simply a tactical oversight, but a violation of the basic logic Augustine outlines. To remove an existing political structure, however flawed, without the capacity to replace it with a more stable one, is to unleash precisely the kind of chaos that just war reasoning is meant to prevent, and that chaos was not abstract.

Inside Iraq, the collapse of order produced sectarian violence, mass displacement, and the fragmentation of civil life. Those who suffered most were not political elites or ideologues, but ordinary Iraqis whose lives were suddenly exposed to forces they could not control. The asymmetry of chaos was on full display. But the consequences did not remain contained.

Regionally, the destabilization of Iraq altered the balance of power in ways that strengthened Iran, empowered non-state actors, and contributed to a broader arc of instability that would later manifest in conflicts across Syria and beyond. The idea that a single regime change could be surgically executed without cascading effects revealed a dangerous underestimation of how deeply political orders are embedded in history, identity, and power structures…and here is where the argument moves from history into present danger.

Strategic chokepoints like the Strait of Hormuz are not merely geographic features; they are levers of global order. Roughly one-fifth of the world’s oil flows through that narrow corridor, making it one of the most consequential pieces of terrain on earth. Under conditions of relative stability, even adversarial states tend to treat such chokepoints with restraint. The game is dangerous, but legible. There is typically one primary actor with the capacity to threaten closure, and that actor is constrained by its own interests. But chaos changes the game.

If a state like Iran were not merely pressured but fractured; if central authority degraded or collapsed, the result would not be a freer or safer Strait. It would be a more dangerous one. Instead of a single actor with a “kill-switch,” you could have multiple actors: factions, militias, proxy groups, each with partial capability and far less incentive toward restraint.

We are already seeing early forms of this dynamic. Control over transit through Hormuz has become selective, politicized, and contingent — more akin to a toll system than a neutral passage. At the same time, threats to shipping, rerouting of energy flows, and fragmented enforcement mechanisms are spreading risk across the system rather than containing it. This is a strictly worse equilibrium.

In game-theoretic terms, a single rational actor with a credible threat can be deterred and bargained with. A fragmented set of actors with partial control and asymmetric incentives cannot. The system becomes less predictable, less governable, and more prone to cascading failure.

In other words, the move from one chokepoint controller to many is not diversification. It is degradation. And this is precisely the kind of second-order consequence that prudence is meant to anticipate.

The Iraq War provides a clear illustration of how these costs manifest at home. American lives were lost. Capital was expended at extraordinary scale. Trust in institutions eroded as the gap widened between what was promised and what was delivered. And again, the burden was not evenly shared. Those who fought the war and those whose economic positions were most sensitive to macro instability bore the brunt.

One might argue that these outcomes were simply the result of poor execution. That with better planning, more troops, or different decisions, the war could have achieved its aims. This response misses the more consequential point.

The failure was not merely operational. It was conceptual. It lay in the assumption that political order could be rapidly engineered from the outside, that the removal of a regime would naturally give rise to a better one, and that the complex fabric of a society could be rewoven under conditions of external intervention.

This is precisely the kind of abstraction Augustine warns against. It substitutes a theory of how things ought to work for a sober assessment of how they actually do.

Prudence, in the classical sense, is not timidity. It does not forbid the use of force. But it demands that leaders account for the full chain of consequences their actions will set in motion. It asks not only, “Is this cause just?” but “What will follow if we act—and if we fail?” In Iraq, these questions were either insufficiently asked or insufficiently answered.

The result was not simply a war that went poorly. It was a war that imposed asymmetric costs on the most vulnerable, both abroad and at home, while failing to secure the durable order that alone could justify those costs.

This is why the lesson of Iraq is not reducible to a debate over intelligence failures or tactical errors. It is a lesson about the limits of power and the necessity of prudence. It is a reminder that political communities are not blank slates, and that the destruction of order is far easier than its creation. Above all, it is a reminder of responsibility.

When a state chooses to go to war, it is not engaging in an abstract exercise. It is making a decision that will reverberate through the lives of its citizens and others, often in ways that cannot be fully predicted or controlled. To ignore the asymmetry of those effects is to abdicate the very duty that justifies political authority in the first place.

Augustine’s insight endures because it is grounded in a realistic understanding of human and political life. Peace is fragile. Order is hard-won. And chaos, once unleashed, rarely confines itself to the intentions of those who set it in motion. The Iraq War stands as a case study in what happens when these truths are neglected, and a warning of how much worse the next iteration could be.