Consider, if you will, a fraught military standoff. A soldier from the German army receives an order from a superior to fire his gun, but he puts it down and walks away. In the United States, he would have just committed the unforgivable and illegal act of insubordination, even if the superior officer weren’t from the same service branch.

But in this scenario, the German soldier didn’t break the rules—he followed them. Military disobedience is actually baked into the German Bundeswehr, or armed forces. And the reasons why can be found in the country’s sinister past.

American military law states that an order can only be disobeyed if it is unlawful. However, the German military manual states that a military order is not binding if it is not “of any use for service,” or cannot reasonably be executed. In fact, if the order denies human dignity to the armed forces member or the order’s target, it must not be obeyed.

In practice, that means that a soldier or armed forces administrator can ignore a superior officer’s order—even if it’s in the midst of combat or is given by a high-ranking official.

That’s not how it used to be. Unconditional obedience to military orders was once a norm going back to the kingdoms that preceded Germany before it became a nation state in 1871. During World War I, Germany executed 48 soldiers for insubordination, and its basic training regimen—designed around unconditional submission to higher officers—was known as one of Europe’s most brutal.

READ MORE: Life in the Trenches of World War I

After World War I, this discipline softened thanks to the Allied forces, which blamed the country’s strict military hierarchy for the ruthlessness of World War I. Under the Treaty of Versailles, Germany was forced to admit guilt for the war and to restrict its military’s numbers and weapons. The country’s military was effectively dismantled, with officer schools shut down and the number of troops reduced to just 100,000.

However, Germany had no intention of following the treaty’s military provisions. Soon after the treaty was signed, German general Hans von Seeckt began to reorganize and secretly rebuild the military with the help of Russia. German companies began producing forbidden arms on Russian soil and German troops trained with Russian soldiers—all in secret.

By the time Adolf Hitler came into power in 1933 with promises to revive the country’s former might, the German public was ready for it. Hitler immediately began to openly flout the treaty. As he brought Germany’s secretive postwar military into the open, they began pledging their loyalty directly to him. From 1934 on, the German military oath was sworn to Hitler himself—and it contained a clause that promised “unconditional obedience.”

That rule was taken seriously during the lead up to World War II and the conflict itself. At least 15,000 German soldiers were executed for desertion alone, and up to 50,000 were killed for often minor acts of insubordination. An unknown number were summarily executed, often in the moment, by their officers or comrades when they refused to follow commands.

This wasn’t always the case. Historian David H. Kitterman’s research on a group of 135 German soldiers who refused orders to kill Jews, POWs or hostages shows they suffered beatings and death threats for defying their superiors, but none were executed. Although insubordination was taken seriously, excuses that soldiers had “just been obeying orders” when they participated in Holocaust atrocities weren’t entirely true.

When the war ended, the Allies assumed control of Germany and decommissioned its entire military. It took a decade for Germany—now split in two—to regain a military, and in 1955 a new Bundeswehr was created.

The new German armed forces were a different beast than their predecessors. German law forbids the use of its military to do anything other than defend Germany itself, though the military does participate in some humanitarian and NATO coalition missions. Instead of blind obedience, the military emphasizes Innere Führung, a hard-to-translate concept that centers the military experience around the inner conscience of each individual.

As a result, many German soldiers refuse combat assignments or disobey orders—with no consequence. Their ability to do so has been repeatedly held up in civil courts (Germany has no military courts) and in the federal government. In 2007, the German federal government even went so far as to state that German law means unconditional authority or loyalty to superiors can’t exist. Soldiers must not obey unconditionally, the government wrote, but carry out “an obedience which is thinking.” However, the policy statement added, soldiers can’t disobey an order merely because their personal views conflict with those of their superior.

Nowhere is that conception of conscientious military service more apparent than at the Benderblock, a Berlin building where participants of a failed attempt to assassinate Hitler were executed in 1944. Today, the building is a museum to German resistance—and every year, it’s the place where new German soldiers are traditionally sworn to their duties.

It’s intentional that their oaths to defend Germany are sworn in a place not of military obedience, but of military resistance. The brutal legacy of two world wars and the Holocaust explains Germany’s reticence to make its soldiers obey orders no matter what.

This story is part of Heroes Week, a weeklong celebration of our heroes in the armed forces. Read more veterans stories here.