The fallout from President Trump’s disastrous trip to Europe continues to poison the trans-Atlantic climate. His comments about Germany have been particularly toxic—and, beyond that, stupid, reflecting no understanding of the country’s strategic importance or its dreadful history.

Chancellor Angela Merkel stated the matter plainly in a speech on Sunday in Bavaria. Europeans “must take our fate into our own hands,” she said, because the “times in which we could rely fully on others … are somewhat over.” This, she added, “is what I experienced in the last few days”—a reference to Trump’s behavior in Brussels and Rome, where, among other bits of rudeness, he declined to pay even lip service to the pledge, enshrined in Article 5 of the North Atlantic Treaty, that the United States would defend any member of NATO that comes under attack.

As if in piqued response, Trump tweeted on Tuesday, “We have a MASSIVE trade deficit with Germany, plus they pay FAR LESS than they should on NATO and military. Very bad for U.S. This will change.” While overseas, Trump had reportedly told Jean-Claude Juncker, president of the European Union, “The Germans are bad, very bad. Look at the millions of cars that they’re selling in the USA. Horrible. We’re gonna stop that.” Press Secretary Sean Spicer denied the report, which appeared in Der Spiegel, but Trump’s Tuesday tweet undercut the denial and underscored his complaint. It wasn’t some loose remark, he seemed to be saying; he meant it.

But Trump’s ire is misplaced or unwise on several levels. First, yes, Americans buy a lot of German cars, but this isn’t because Germany is dumping BMWs and Volkswagens on the U.S. market; it’s because a lot of Americans like those cars. Second, as my colleague Daniel Gross has pointed out, lots of those German cars are made in the United States; a BMW plant in South Carolina—the company’s biggest plant in the world—churns out 400,000 cars a year.

The thing is, Trump knows this. When Merkel visited Washington in March, she brought along the CEOs of BMW, Siemens, and Schaeffler, an industrial-parts manufacturer, who met with Trump for an hour, briefing him on their $300 billion investment in the American economy and the 750,000 American jobs that their plants had created. By all accounts, Trump was impressed.

Germany’s trade surplus—which last year totaled $65 billion with the United States alone—is a problem, but it’s not the result of explicitly stacking the deck. Rather, it’s rooted in German fiscal and monetary policies that encourage savings and suppress consumption, including of imported goods. These policies stem from a phobia of inflation dating back to the 1920s, when the Deutschemark collapsed (in one year’s time, its value fell from 4.2 per dollar to 4.2 trillion per dollar), paving the way for the rise of Nazism. German bankers of the 21st century need to loosen up, but this is a process to be encouraged through calm, professional trade negotiations, not ALL-CAPS bluster.

On military spending, Germany does come up short. Though it is Europe’s economic powerhouse, its defense budget—37 billion euros ($41.4 billion)—ranks third, behind that of Great Britain and France. But again, historical context is important. Until recently, the overwhelming consensus, inside the country and throughout the world, was that Germany should not spend much money on defense. The German constitution prohibited the military from deploying troops in foreign countries; when this stricture was relaxed, soldiers were still forbidden to kill enemy soldiers.

As with hypersensitivity to inflation, the aversion to militarism is deeply rooted in historical memory. The vast majority of Germans are resistant to taking the slightest step toward a revival of Germany’s imperialist path—either Hitler’s or Bismarck’s. And, given the devastation that German aggression wreaked across Europe twice in the 20th century, this aversion was shared by all of the Western allies. An adage (not quite a joke) from the Cold War held that NATO had three purposes in Europe: to keep the Americans in, the Russians out, and the Germans down.

Many in Europe, most of all the Germans themselves, still have a hard time wriggling out of this view of the country’s place in the world. In recent years, they have changed their constitution to allow foreign military deployments, they have further relaxed laws allowing troops to engage in combat, though under restricted circumstances, and they have raised their defense budgets substantially (8 percent in just the past year). But to push Germany into taking on more responsibilities—which, in the easing of an American role, could evolve into the dominant responsibility—is to toy with deep issues of national character and a remarkable security structure on the continent.

Perhaps the most wondrous thing about the world that took form after World War II has been the absence of war between the longstanding rivals in Europe—not just the absence of wars but the disappearance of the notion that European wars were inevitable. This feat didn’t come about by some miracle or accident. It was the result of painstaking effort to build an alliance based on shared values and common interests, requiring trillions of dollars in aid and investment, the maintenance of massive military bases, and—in particularly trying times—a crisis or two that risked another, far more cataclysmic war. It is this alliance—and the international order on which it stands—that Trump’s tantrums and indifference are endangering.

Certainly the United States has spent a disproportionate share in the upkeep of this project, and Trump is far from the first president who has urged the allies to up their ante. (Every president in the last 40 years has set numerical goals for military spending. Jimmy Carter pressed the allies to spend 3 percent of their gross domestic products; Barack Obama pushed for 2 percent, a plea that Trump is renewing—and may see satisfied to a greater extent, owing less to his snarling rhetoric than to Moscow’s renewed growls.) One positive outcome that may emerge from Trump’s hostility to the European leaders—and to the concept of the European Union—is that those leaders may finally get serious about the requirements of a European pillar to their defense. They may heed Merkel’s plea to take their own fate into their hands.

Ultimately, though, the Europeans can’t do this on their own. They lack the resources, the political will, and the ability to coordinate a common approach. The Germans might be able to pull off that role as leader, but their history stands as an obstacle—and, given that history, this is probably a good thing. They know their limits, and for that reason Merkel and other officials backpedaled a bit from her speech on Sunday, stressing that of course trans-Atlantic ties will, or anyway, must, survive. But in her Sunday speech, she was only acknowledging what the other European leaders realized last week (you could see it on their faces as they watched Trump speak)—that the alliance will be in some degree of abeyance as long as this guy is president.

It may be no coincidence that Russian President Vladimir Putin’s chief foreign-policy goal is to restore the old Soviet Union. He can do that only if the European Union is weakened and the ties between the United States and Europe are severed. He may have reason to believe that his dream might come true. Whatever the probes reveal about Trump’s ties or obligations (or lack of any connections whatever) to Russia, his signs of indifference to the fate of Europe are no doubt causing Putin to salivate more than he thought he ever would.