On multiple occasions after President Trump launched a massive air campaign against Iran this past weekend, retaliatory attacks by simply constructed Iranian drones have penetrated American defenses with serious results. For example, at least six U.S. soldiers died, and others were wounded, in an Iranian strike Sunday on a command facility in Kuwait. CNN reported that the Americans received no warning of the incoming drone. According to CBS News, the fortifications around the facility protected it from car bombs but not from a direct overhead strike. “We basically had no drone defeat capability,” an unnamed military official told the network.

At a news conference this week, Defense Secretary Pete Hegseth seemed to downplay the significance of the event, saying, “You have air defenses, and a lot’s coming in, and you hit most of it.” He went on to say, “Every once in a while, you might have one, unfortunately—we call it a squirter—that makes its way through.” Yet the failure to beef up relevant defensive measures in a facility located so close to Iran is a curious lapse in planning.

Brynn Tannehill: The dangerous mismatch between American missiles and Iranian drones

When a complex system starts to decay, the first signs are usually subtle. In the third century, after the Roman empire had reached its geographic maximum, literacy began to decline across Roman society. Education levels fell not only among soldiers, but among officers, aristocrats, and even emperors. The Roman army still looked formidable for years afterward. It had good equipment and could march well. Yet it was no longer as advanced relative to Rome’s enemies as it had once been. It fought as hard as ever, but less effectively.

The capabilities of the U.S. military are still far superior to Iran’s. Yet certain developments in the American bombing campaign against Iran—a country seemingly rendered almost helpless after Israel destroyed most of its air defenses last year—are revealing what look like signs of strain.

The U.S. military’s supremacy over foreign rivals is built on intensive training and the manipulation of advanced technology. By contrast, Hegseth has been stressing lethality and a warrior ethos instead of learning and reflection, to the point of blocking U.S. military personnel from taking courses at the most elite American universities. Yet the events of the past week underscore how shows of force alone may not defeat even militarily inferior enemies.

In Bahrain, a lone Iranian drone penetrated the headquarters of the U.S. Fifth Fleet, which oversees 2.5 million square miles of the world’s oceans. The incoming weapon destroyed an AN/TPS-59 radar unit intended to provide 360-degree air surveillance for U.S. forces. In a moment, Iranian equipment that cost perhaps $30,000 devastated a piece of U.S. military hardware estimated to be worth tens of millions of dollars.

The current campaign against Iran began on a schedule of America’s choosing. Trump announced his intention in January to send more U.S. forces to the region. Positioning two aircraft-carrier battle groups took some time. Suicide drones are widely known to be among Tehran’s most effective weapons; Russia has used the Iranian-made equipment to devastating effect against Ukraine.

A separate worrisome incident hints at a different set of vulnerabilities. On Sunday, three F-15E aircraft were shot down in short succession in a single friendly-fire incident over Kuwait. These were among the more advanced aircraft that the U.S. Air Force possesses. Fortunately, no crew members were killed, but the mysterious event raises uncomfortable questions. Were the three F-15Es flying so close that they could all be taken out at once? How well were American forces communicating with Kuwaiti allies? Perhaps the incident simply resulted from a misunderstanding in a moment of conflict, but America’s ability to collaborate effectively with other countries is very much in doubt under Trump.

The forging of military and diplomatic alliances with other governments with which the United States shares interests has been another major source of American strength since World War II. Trump’s campaign in Iran has been closely coordinated with one longtime ally, Israel. But his administration has deliberately spurned many other traditional U.S. partners, most notably European ones, in ways that have significant military consequences.

Karim Sadjadpour: Trump has lost the plot in Iran

When Trump announced that the bombing of Iran had started, European states conspicuously refrained from endorsing the operations. The leaders of the three largest European democracies—Germany, France, and the United Kingdom—jointly declared that they were not participating in the strikes. A top European Union official issued a vague but reticent statement saying that “the latest developments across the Middle East are perilous.”

Since then, Britain has reluctantly agreed to let the U.S. use a base on Cyprus for operations, but this limited help has clearly disappointed the Trump administration. This week, the president belittled the so-called special relationship with Britain for being “obviously not what it was.” Hegseth complained that America’s traditional allies “wring their hands and clutch their pearls, hemming and hawing about the use of force.” But he and Trump should hardly be surprised at the lack of enthusiasm. The president has repeatedly cozied up to Russian President Vladimir Putin, the greatest security threat to democratic Europe, and has sought to take Greenland from Denmark, another longtime ally. Americans and Europeans might still refer to each other as “allies,” but the signs of rot are obvious.

Just as the Roman empire survived for two more centuries after it started to decline, the United States isn’t in danger of imminent collapse. But Trump’s rejection of planning, expertise, and diplomacy is beginning to have real-world consequences.