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This week in Washington, the West’s foremost military alliance marked its 70th anniversary. But it was hardly a jubilant celebration. Ahead of NATO ministerial meetings held in the American capital, the alliance’s secretary general, Jens Stoltenberg, addressed a joint session of the U.S. Congress on Wednesday with a note of concern. “We have to be frank,” Stoltenberg said. “Questions are being asked on both sides of the Atlantic about the strength” of the alliance.

Those questions have been largely prompted by President Trump, who came into the White House having called NATO “obsolete.” Throughout his presidency, he has questioned NATO’s relevance and bullied long-standing allies with threats and tariffs.

Nevertheless, the commemoration of the anniversary led to dignitaries from the bloc’s 29 member states issuing paeans to the great unity and strength of the alliance. But as NATO turns 70, there’s little certain about the course of its next seven decades.

There are obvious cracks in the alliance. While previous U.S. presidents have urged their European partners to increase their defense spending, Trump’s relentless, angry insistence that Europe pay its fair share — that is, separately set its defense budgets to 2 percent of national GDP — darkened the mood surrounding the Brussels-based bloc. It led many in Europe to bemoan Trump’s transaction-like view of things and seeming inability to recognize the implicit strategic value of a pact that guaranteed U.S. security through the Cold War and supremacy thereafter.

But at NATO meetings this week, Vice President Pence renewed the administration’s impatient messaging. “NATO is a mutual defense pact, not a unilateral security agreement,” he said, in what was a read as a jab at Germany in particular for its unwillingness to reach the 2 percent threshold.

On the same day, in a riposte to Trump’s bullying diplomacy and rising nationalism in the West, the French and German foreign ministers unveiled at the United Nations an initiative aimed at bolstering “multilateralism.” They announced plans to create a network of countries that would cooperate in the fight against inequality, climate change and the risks posed by new technologies.

This new grouping would “show the world what could be the consequences of unilateralism and isolationism enabling nationalism and extremist speeches to flourish,” said French Foreign Minister Jean-Yves Le Drian, in what can only be read as a broadside at Trumpism.

Another more immediate source of friction in NATO centers on Turkey’s purchase of the Russian S-400 missile system, which has frustrated the United States. The Trump administration recently threatened to halt the delivery of F-35 jets to Turkey, further exacerbating tensions between two ostensible NATO allies whose relationship has steadily deteriorated in recent years. In remarks viewed by Turkish officials as scolding and condescending, Pence asked Turkey whether it wanted “to risk the security of that partnership by making reckless decisions.”

Europe is falling out love with America under Trump. Take, for instance, Germany. In a recent Pew survey, 73 percent of Germans polled viewed relations with America as “bad” and 47 percent of Germans wanted “less cooperation” with the United States. The standard line that has emerged from numerous European leaders is that the continent needs to take more responsibility for its collective future — a reflection of shifting geopolitical realities, yes, but also of fears sparked by an erratic White House.

But Americans remain broadly in favor of NATO. According to a new poll conducted by the University of Maryland, more than 8 in 10 Americans support NATO. Moreover, when posed with choices of how to face NATO, a significant majority disapproved of retreating from the alliance. “For both Democratic and Republican respondents, threatening to disengage was the least popular option, with only 4 percent of Democrats and 21 percent of Republicans saying that they found it to be the most convincing,” my colleague Emily Tamkin wrote.

Stoltenberg’s invitation to address Congress stemmed from a bipartisan consensus on the Hill that wholly backs the alliance.

Trump’s rhetoric notwithstanding, U.S. commitment to European security has not fundamentally changed. The Trump administration, if not the president, has been tough on Russia and continues to fund initiatives to help guarantee European defense. “There’s this argument within the policy community about policies versus words,” Rachel Rizzo, a fellow at the Center for a New American Security and an expert on NATO matters, told the Atlantic, suggesting the president’s bark was far worse than his bite. “Trump uses harsh words all the time. It’s something that we’ve gotten used to.”

NATO’s critics are adamant that it has outlived its usefulness. Doug Bandow, a NATO skeptic at Washington’s libertarian Cato Institute, argued that the Russian threat is grossly overstated and that Europe is entirely capable of hedging against it on its own. Beyond that, he wrote, the United States would be better off becoming “an associate member of NATO” and forging “new agreements with Europe to cooperate where interests coincide.” Bandow concluded: “NATO has reached the venerable age of 70. It should be pensioned off and replaced with security architecture developed to meet current challenges.”

Whatever the case, NATO’s focus is extending further and further away from Europe. An alliance once arrayed against the threat of the Soviet Union may still be preoccupied with a far weaker adversary in the Kremlin but is also entangled in conflicts in the Middle East and Afghanistan — with little definitive success. While the Trump administration tries to extract itself from both those theaters, the key focus of U.S. security policy will increasingly shift from the Atlantic to the Pacific as Washington plots ways to check the perceived threat of an emboldened China.

European officials and analysts are aware of the need to pivot east as well. But it’s hard to see what role NATO members such as the Netherlands or Spain, let alone Iceland or Slovenia, may play in strategic deliberations regarding the South China Sea.

“Europe’s biggest worry is that in a world of great power competition between the U.S. and China, it will be left by the wayside,” wrote Politico’s Matthew Karnitschnig.

NATO’s boosters anchor their faith in the alliance in its past and a sense of its values. “History provides few achievements that compare to those seven decades of peace,” wrote Adm. James Stavridis, a former NATO commander. “They were built not on the ambitions of cold-eyed leaders but something more noble. NATO is a pool of partners who . . . by and large share fundamental values — democracy, liberty, freedom of speech, freedom of expression, gender equality, and racial equality.”

But the alliance isn’t as like-minded as it once may have been. Trump’s bickering with Western European partners laid bare a profound ideological rift. And the illiberal turn in countries such as Hungary and Turkey point to the fragility of democratic norms within the alliance, never mind the wider world beyond it. Rather than bolstering NATO’s credibility, efforts to expand its membership to tiny countries farther east — including the newly christened North Macedonia and potentially Georgia — underscores the extent to which NATO may simply be a Cold War anachronism rumbling along in a somewhat confused 21st-century afterlife.

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