Laura Rosenberger is director of the Alliance for Securing Democracy and a senior fellow at the German Marshall Fund of the United States.

BRUSSELS — Sitting on the grounds of the new NATO headquarters this week, I felt like I was watching a split-screen TV. Here were NATO Secretary General Jens Stoltenberg and numerous other leaders projecting confidence in NATO’s mission, discussing the importance of unity and cohesion, and underscoring the democratic values to which the alliance is deeply committed. And there was President Trump, lobbing threats against our allies and the alliance itself, including that he would “do his own thing” separate from NATO if allies did not meet defense spending targets.

Trump, who has long believed that our alliances are more of a burden than a benefit, was yet again seeking to create a crisis where none existed, purely for his own political benefit and so he could once again prove that he “alone can fix it.” Meanwhile, our 28 allies showed up prepared for the worst but committed to showing NATO’s best.

Just a glance at the summit’s declaration, to which Trump and our allies agreed, should have been enough to show Trump the many ways NATO is working to advance the interests of the United States and our allies. NATO leaders agreed to a long list of commitments: underscoring their resolve in the face of Russia’s aggression, including standing for Ukraine’s territorial integrity; recommitting to fighting terrorism, including through a new counterterrorism mission in Iraq; outlining numerous operational commitments to improve the alliance’s readiness; emphasizing the importance of cybersecurity as an area of the alliance’s focus; establishing “counter hybrid support teams” to help allies prepare for and respond to hybrid activities; enhancing NATO’s forward presence in the areas adjacent to Russia; and plenty of other pledges of cooperation. Reading the declaration is a cogent reminder of the work NATO does every day, invisible to most of us, to stop threats before they land on America’s doorstep. And it’s a reminder that, despite Trump’s theatrics, this work goes on.

And contrary to Trump’s declarations at his news conference Thursday that NATO defense spending has increased because of his demands, the reality is that the alliance’s members have been increasing spending since 2014, when they agreed to a target of 2 percent defense spending by 2024. So far, spending has increased by $46 billion.

Trump’s flame-throwing undermined what should have been one of the summit’s most important outcomes: unity. The two versions of the summit collided when German Defense Minister Ursula von der Leyen, after underscoring the importance of unity, cohesion, and solidarity as summit outcomes, was asked about Trump’s accusation that Germany was captive to Russia, which he had made while she was on stage speaking. Genuinely puzzled, she was at first at a loss for words, and then dismissed the notion as ridiculous — appropriately so. (The president had claimed that German imports of natural gas from Russia “can’t be explained” since “we’re supposed to protect Germany, but they’re getting their energy from Russia.”) While concerns about Germany’s pipeline deal with Russia are legitimate, Trump’s broad accusation, and the manner in which he delivered it showed his goal was to pick a fight, not meaningfully discuss these concerns. The juxtaposition of allies who genuinely believe in NATO and are working hard for it, with a U.S. president who seemed to be at the meeting only to blow it up, was stark.

What it was not, unfortunately, was surprising.

Trump’s behavior at NATO is just the latest in a pattern in which the president manufactures crises to advance his own political purposes. In this case, his goal seems to be feeding his “America First” base by showing that he was standing up to Europe, or fulfilling the idea that, as one of his advisers reportedly put it, “We’re America, bitch.” But sitting at NATO this week, and in conversations with foreign officials in the run-up to the summit, it was clear to me that this strategy is not only isolating the United States, but eliminating the very power that has provided for our peace, prosperity and security for decades. And that erosion of power could last longer than Trump’s tenure.

It does not have to be this way. Even within the United States, Trump is decidedly at odds with the American people over our alliances with Europe. An October 2017 Chicago Council survey found 69 percent of Americans say NATO is essential for U.S. security, and 59 percent say the United States should maintain a firm defense commitment to NATO allies even while asking for more burden-sharing. As Trump was arriving at NATO, the Senate voted 97 to 2 to reaffirm the United States’ “ironclad” commitment to mutual defense under Article 5 of the North Atlantic Treaty. And as NATO leaders were going into emergency session to address Trump’s threats, bipartisan members of the Senate Armed Services Committee were reinforcing the Senate’s strong commitment to NATO, stressing they had traveled to Brussels explicitly to send that message — in what felt like another screens-colliding moment here.

The risk is that, through his theatrics and aggressive rhetoric, Trump will create the very conditions he claims already exist — that the United States will become the problem Europe believes it needs to manage. Despite their best attempts to act as though it’s business as usual, our allies at NATO spent too much time focused on Trump, rather than focused on the threats from our shared adversaries. Trump’s threats Thursday morning and the emergency session NATO called afterward were a distraction from important discussions happening on Ukraine and Georgia (where the threat of Russia looms large) and Afghanistan (where NATO continues a counterterrorism mission). And it once again shook the confidence of our allies.

And that hurts the United States more than anyone else. Trump’s comments risk eroding public support for the United States as an ally in Europe — something that will be necessary should NATO ever need to commit troops under Article 5. And increasing defense spending will require domestic political support — something that will be harder to achieve when Trump is laying siege to the alliance itself.

Trump’s misleading comments disparaging NATO may also begin to erode public support at home. Canadian Foreign Minister Chrystia Freeland remarked here that NATO needs to be an alliance not just of leaders, but of people. But Trump’s rhetoric is doing potentially lasting damage to the very basis of that foundation. Former U.S. ambassador to Russia Michael McFaul went so far as to say that “Trump has done more damage to NATO in 18 months than Soviet & Russian leaders achieved in seven decades.” In doing so, Trump has advanced Russia’s interests — not ours.

Read more:

No one will win Trump’s trade war with Canada

 Yes, Russia is a threat to NATO. So are the alliance’s anti-democratic members.

Trump has no friends in England. Too bad Boris Johnson is in hiding.