Several months ago, I discussed how wars leave a demographic shadow even decades after the end of the fighting. Today, I’m going to expand on that idea by explaining how conflicts also have a disproportionately long impact on the political psyche of a country.

First, let’s examine this graph, the product of a psychological study by the New York Times and Columbia University. The most important finding is that people develop their deepest political beliefs between ages 14 and 24.

The idea makes intuitive sense. As children enter their adolescence and early adulthood, they make a conscious effort to determine who they are and what they value. The lessons they acquire in that time stick with them throughout the rest of their lives. To use a more scientific explanation, the neural pathways in a person’s brain remain malleable and growing until about age 25, at which point they become static and it becomes harder to learn or change behavior.

The key point here is that the formative political ages overlap almost exactly with the ages most affected by conflict and warfare. Of course, ages 18-25 are historically the most common ages of military service, but I’m not just talking about soldiers. In times of major conflict, all young adults, not just soldiers, have had to bear the brunt of the effort. Young adults enjoy peak health and energy, but are also inexperienced and not yet integrated into long-term careers or families. That makes them an ideal labor pool for any new war-related jobs. It’s inevitable that in their course of their wartime-related work, these young people will have experiences that influence their political perspective.

If your strongest political views appear during your young adulthood, and warfare impacts young adults most severely, the implications are obvious. Demographics mean that military conflicts have a disproportionately greater and longer-term influence on a nation’s politics than almost any other event. Five to ten years after the end of the war, just as the immediate effects of a conflict begin to fade, the generations disproportionately molded by the war begin to enter politics and leadership positions, creating secondary legacies that last for decades. Many wars also have tertiary legacies, where generations born after the war recollect (and often distort) the conflict, but that’s a topic for another time.

The political-demographic impact of a conflict is difficult to quantify, since political views are themselves vague or even subconscious. One might instead look to the high positions of power achieved by those shaped by the war. Seven future U.S. presidents served in World War II, and most of them (Kennedy, Ford, Nixon, and Bush) were under the age of thirty when they did so. It cannot be doubted that these men’s wartime experience left a tangible, if hard to articulate, impact on their lifelong political views. Kennedy, Ford, and Bush all participated in multiple combats, and the trauma and violence of the war surely left a permanent impact on these young men. Bush, for example, began piloting bombing missions against the Japanese at age 19, and at age 20 was shot down over the Pacific. Although Bush was rescued by U.S. Navy ships, several men in his squadron were captured and executed by the Japanese. As his White House speechwriter four decades later recalled, “[Bush always] became very, very emotional whenever he talked about the military.”

The point I hope everyone walks away with is that more than other political events, military conflicts have long-term political consequences. Those political effects come in waves and can actually grow stronger over time, as the generations who spent their formative years in the conflict achieve positions of ever-greater power and influence. The most important legacies of the a conflict are not the landmarks or the photos or objects from the years of the war, but the men and women indelibly marked with the memories of that time who use wartime experience as their lodestar for the future.