On a beautiful winter dawn three decades ago, I found myself in one of the more dreadful battlefields scenes of the 20th century—the road out of Basra, Iraq. We fought there the night before, against an enemy I didn’t hate, in a land I didn’t care about, rich in a commodity that didn’t matter to me.

The scene defies easy description. The dead lay on the road, beside vehicles and in ditches, in clustered masses that reminded me of sepia-tinted photos of Antietam. Civilians were sprinkled through the columns of dead. We couldn’t readily determine if they were fleeing a potential battle in Basra, carried there as hostages, or as civil employees of this murderous regime. Many of the dead were hardly recognizable as human, much less military or civilian.

These deaths were from a fight between Iraqi Republican Guards and the division in which I served as an infantry captain. Many were also killed by the undisciplined Iraqis who helped destroy their own column. I have no regrets about our cause or my role in it, but that scene has revisited me on each of the more than 12,000 days since. That remembrance is useful.

I am deeply grateful for the experience of that war. It is central to the man I am today, how I view the world, what I wish for, and what I expect for my own children. It is also key to my understanding of one deep lesson about the 20th century and how we must embrace that lesson to deal with the events that trouble us today.

The central political lesson of the 20th century was simple and hard. Unless you surround yourself with a strong, liberal, constitutional democracy, expect disaster. The world can be hard enough for citizens of democracies. We were too often swept into the fires of war, but without the promise of a liberal democracy, the future portends nothing but eventual disaster.

I pause here to remind readers that a liberal, constitutional democracy is one of laws, not men, maintains separations of powers, protects speech, and ensures rights for all citizens, not just those in the majority. Our Constitution offers the highest form of a liberal democracy, which is why I swore a lifetime oath to defend it.

If you lived in one of the authoritarian governments of the 20th century, you must have expected a simple future. Your sons were likely to be maimed or die in war, your cities destroyed, your families scattered, your lands burned and your wealth evaporated. It could be worse, though. Your religion could be extinguished, your grandchildren raised by the enemy and your very existence denied. This risk was the experience of several billion humans of the last century.

This is the experience of many in this century as well, and explaining it necessarily means opening raw feelings among many readers. The Germans of 1945 suffered not because their enemies were evil—though the Soviets were. They suffered because they succumbed to authoritarian voices in an election 12 years earlier. They paid too little attention to their democracy, the rule of law and the protection of minorities. The majority of Germans did not vote for Hitler’s party in 1933, but enough succumbed to his evil allure to doom all of them to ruin.

The Palestinians in Gaza suffer today for exactly the same reason. Indeed, Hamas received a higher vote share in 2006 Gaza elections than Hitler did in 1933 Germany. It is important to view the Palestinians today in the same way we viewed Germans in 1933. They are two peoples, insufficiently appreciative of the blessings of peace, who collectively traded away the opportunity of a peaceful democracy.

It is true that, both Germans and Gazans felt ill-treated by peace agreements, had angry nations on their borders and had little experience with the institutions that bolster democracy. Those facts make for interesting social science discussion, but they offer no excuse for the murder and ruin that followed. Russia must be viewed in the same way, though the elections that brought Putin to power were far less free than either those in 1933 Germany or 2006 Gaza.

No one should have illusions that opposing Hitler or Hamas was easy, or safe. Many of those who did so paid with their lives. But, many of those who supported them also paid with their lives, and they pay for it still. It is a hard, grim calculus, that history demands we each consider. It is also a reminder of Aristotle’s proposition that courage is the first virtue from which all other virtues spring.

Too few among us really understand the fragility of constitutional democracy and the difficulty of creating and sustaining it. Sure, there is much reflexive tongue wagging about the importance of democracy, but little of it carries the urgent memory of having seen what the collapse of democracy means to individuals, families and civilization. I have that urgent memory.

My world view on democracy is colored by having personally experienced the grim, sad towns of East Germany, the bandit filled roads of Zimbabwe, the peacekeeping watchtowers in western Sinai, the open desert northwest of Kuwait and at the DMZ in Korea. I am blessed with experiences that make me profoundly grateful for our liberal democracy. Having seen close up the world without them keeps my eyes wide open about the risks to liberal democracy here and abroad.

Today American foreign policy makes these connections. The Biden administration is right in linking Hamas and Russia. They both threaten the liberal constitutional order worldwide. In this way, American foreign policy has returned to its post-World War II bipartisan roots, moving away from the neglect of the Obama administration and the incoherence of the Trump administration.

It is late in history for Americans to struggle with the substance of this foreign policy. In a war between a liberal constitutional democracy and a murderous dictator, there is but one choice. It is no coincidence that those Americans who oppose Ukraine while favoring Russia are perfectly comfortable attacking our capital and overturning American elections. Nor is it a coincidence that those Americans supporting Hamas fill their throats with vile, ugly, bitter anti-Semitism.

Both groups reject who we are as Americans, and more importantly they reject the ideals that allow us to form a more perfect union. On this Veteran’s Day we must be reminded that sustaining democracy requires courage. We need that virtue today. We must reject those cowards who would end our democracy at home and abandon those abroad.