When the winter comes and the fog clears, those of us who live near the Carlsbad coast north of San Diego can see Navy ships traverse the channel separating Catalina and San Clemente Islands from the mainland. I have long felt a particular pride watching those ships designed, paid for, and manned by Americans because they represent how all of us, together, contribute to our country’s protection. 

But I felt something very different when I looked out at the channel during the last weekend of January. As I read about U.S. agents killing another civilian, Alex Pretti, I wondered whether our leaders might decide to use the USS Makin Island’s aircraft against a politically inconvenient group of U.S. citizens, whose lives the planes had been designed to protect. 

As a Roman historian, I know a powerful nation can make the shift from protecting to attacking its citizens very quickly — as what happened in the 1st century B.C.E., when the angry, ambitious consul Sulla turned Romans against one another to advance his personal political goals. 

For nearly 400 years, starting in the 5th century B.C.E., the Roman Republic had refrained from using its armies against Roman citizens, because Romans believed that all citizens were equal political stakeholders in their state. But as Rome’s economy grew increasingly unequal in the 2nd century B.C.E., a series of political tensions created the conditions for that to change. 

After Romans elected the general Marius in the century’s final decade, he broke with centuries of Roman precedent and recruited soldiers who needed money, then used his financial leverage to send them into the streets to intimidate Romans who opposed his policies. 

It took less than 20 years for the general Marius’ brand of intimidation to turn into outright attacks against civilians by soldiers. In 88 B.C.E., after Rome awarded the consul Sulla a lucrative military command, allies of Marius forced a vote to transfer the command to Marius. Enraged and terrified, Sulla traveled to his army and “urged them to be ready to obey his orders.” The soldiers, the historian Appian wrote, “understood what he meant”— that Sulla wanted them to seize back the power he had lost — and “ordered him to lead them to Rome.” 

Shocked to see a professional army daring to attack Rome’s center of government, civilians barred the city’s gates and fought Sulla’s forces hard, taking up positions on apartment rooftops and bombarding the attackers with projectiles. Sulla “erupted in a passion and, having surrendered to his anger,” ordered his archers to fire burning arrows at the assailants. Hundreds, perhaps thousands, of Roman citizens lost their homes and lives because of their brave fight for their Republic’s principles. 

The city quickly fell under Sulla’s control. He then condemned a small group of his most hated opponents to death and set off for his command in Greece. Almost as quickly, however, his opponents mobilized their own army, marched on Rome, began their own set of mass executions of political opponents, launching a six-year civil war. 

When Sulla finally recaptured Rome, he summoned the senate to the Temple of Bellona, a shrine dedicated to the goddess who embodied the brutality and destruction of war, to tell the senators he was assuming the office of dictator so he could restore the Republic. They listened in terror as Roman soldiers tortured thousands of Roman citizens to death in the circus adjacent to the temple.

Looking out my back window at the USS Makin Island, a single ship with far more firepower than Sulla’s entire army, this long-ago civil war haunted me. Romans had thought that the most fearsome weapons they used against others would never be turned on themselves. But Sulla’s story shows that leaders guided by emotion rather than principle will use any weapon at their disposal, until citizens stop resisting or soldiers stop listening. 

Now, and always, the only thing holding us back from the Romans’ fate is a shared belief in our common, collective ownership of the American Republic, created by and entrusted to its citizens. All of them.

Watts is a historian and distinguished professor at UC San Diego. This was written for Zócalo Public Square.