A new analysis by Lawrence D. Freedman, emeritus professor of war studies at King’s College London, argues that Donald Trump faces the danger of becoming caught up in another long-running conflict. The warning centers on the idea that even leaders with major military strength can underestimate how quickly a war can expand and how hard it can be to bring to a close.

Freedman’s argument points to what he describes as the “short war” illusion. In this view, governments with powerful armed forces may assume that military action will be swift, controlled and decisive. But conflicts often develop in ways that are difficult to predict, turning limited objectives into open-ended commitments.

The concern is that a president who expects fast results could instead end up managing a drawn-out struggle with rising political, military and strategic costs. That is the broader danger behind the term “forever war,” which has become shorthand for interventions that continue far beyond their original aims.

The assessment highlights a familiar problem in modern warfare: starting a conflict can be easier than ending one. Freedman’s warning suggests that any leader weighing military power must also consider the risk that a supposedly short campaign can become a lasting entanglement.