A year ago, President Trump told fellow NATO allies to more than double their defense spending as the United States looked to draw down American military forces in Europe.
This week, at a NATO summit in Ankara, Turkey, top officials at the military alliance will try to show that countries are paying up.
“I think we are in pretty good shape,” said Mark Rutte, the NATO secretary general, in Washington late last month, after plying Mr. Trump with data on the spending advances. “And if there are one or two who need a bit of encouragement, I will do that discreetly, and I can assure you that it’s tough but discreet.”
“This is the first task of every government — to keep the nation safe,” Mr. Rutte said.
The stakes are high for Mr. Rutte and the alliance. Mr. Trump demanded that the allies increase military spending to 5 percent of their gross national product by 2035. Meeting that target will determine how quickly Europe can credibly deter adversaries without the level of military support that the United States has provided since NATO was created 77 years ago.
Some countries, like Germany and the Baltic nations, are making significant progress, shelling out large amounts of money to bolster their militaries with new weapons and additional troops, and increasing NATO’s spending on countries’ armed forces by $90 billion in a single year.
Others, like Albania and Slovenia, are struggling.
Still others, like Britain and France, are trying but face serious budgetary problems.
And a few have padded their budgets with projects that stretch the definition of military investments — even if they technically might pass muster under new NATO spending guidelines approved last year.
Those guidelines direct allies to spend 3.5 percent of G.D.P. on direct military priorities like troops and weapons. The allies can also spend an additional 1.5 percent on defense-related projects like improving transportation routes that would carry military materiel to a battleground or bases, bolstering civilian infrastructure from cyber attacks, refurbishing parking garages to create bomb shelters and building hospitals that, in part, care for veterans.
That’s where some countries are pushing the boundaries.
Take, for example, the Czech Republic’s plans to upgrade train tracks that take tourists to a 14th-century castle.
The rail improvements to the town of Karlstejn were part of a $1.1 billion transportation package that the Czech government cast as defense-related expenses to meet the spending targets.
While some routes in the package could, potentially, be used by armed forces, when it comes to the tracks to Karlstejn, “it’s impossible to find any military dimension of that at all,” said Mojmir Hampl, the head of the independent but state-funded Czech Fiscal Council, which audits the Czech government.
The United States spent just under 3.2 percent of G.D.P. on core defense priorities last year, according to the latest figures available.
NATO officials said that nearly all allies agreed it was past time to spend more on defense, which was underfunded for years, and especially as Russia has brought war to the alliance’s border with Ukraine.
Countries that do not appear to be making an effort to increase defense spending could face further U.S. military cuts. Countries that do not appear to be making an effort to increase defense spending could face further U.S. military cuts. Several senior U.S. officials, including one publicly at Tuesday’s NATO summit, suggested that financial support to allies to buy American weapons would be used as leverage to make sure lagging countries step up. The two others spoke on the condition of anonymity to discuss sensitive political matters. One of the officials said potential U.S. loans through the Foreign Military Financing program could be at risk.
The consequences of both defying Mr. Trump and delaying long-needed defense investments are intertwined. The mercurial president is already pulling out weapons and threatening to withdraw American forces from Europe, where Mr. Rutte has said militaries are unable to defend themselves from potential aggressions without the United States.
“Let’s be honest — the money is not the biggest issue from a NATO perspective, although politically it’s become that because of Trump,” said Paul Savereux, who worked on the alliance’s internal auditing process for more than 20 years before retiring in 2023. “The reality is, we want NATO to have the forces it needs to be able to do whatever it wants to do.”
Germany is expanding its forces and spending billions of dollars on weapons and new equipment. The three Baltic nations — Estonia, Latvia and Lithuania — are buying so many drones, air defenses and ammunition rounds that each country is projected to reach the target of 5 percent G.D.P. this year. Poland, Denmark and Norway are not far behind.
They are all part of what is being called “the 3.5 club” — countries that are making strides to meet the direct military spending requirement.
“We are really hoping that all the allies will do the same,” Hanno Pevkur, Estonia’s defense minister, said at NATO headquarters in June. “It is necessary for the alliance.”
Prime Minister Pedro Sanchez of Spain has said he does not need to spend 5 percent G.D.P. to fund his military priorities. But NATO officials say Spain is making progress in its defense spending.
Some of Europe’s largest economies have had problems.
Britain’s defense secretary resigned in June, frustrated with what he said was the government’s sluggish efforts to build up its military. The country, which has struggled to recruit and retain troops, is projected to spend 2.7 percent of G.D.P. on priority defense needs by next year and through 2029. It remains unclear how soon Britain might reach 3.5 percent.
The Czech Republic is one of three allies that officials in June said had failed to spend even 2 percent of G.D.P. last year on direct military needs — a benchmark set in 2014 that was so low that Mr. Trump complained after he came into office in 2017 that the United States was shouldering more than its share of the NATO burden.
Repeated requests for comment from the Czech government were unsuccessful. Prime Minister Andrej Babis told the Financial Times in the spring that his country was likely to fall short again in 2026, and suggested that his status of being a “Trumpist” might spare him any fallout from the American president.
The U.S. ambassador to NATO, Matthew Whitaker, noted on Wednesday that some allies “either are not spending enough right now or don’t have a credible path” to reach the investment pledge.
“President Trump fully expects that all allies will step up immediately and get on the path to 5 percent, and do it with urgency,” Mr. Whitaker said at a media briefing.
Albania and Slovenia also failed to meet the 2 percent mark in 2025, NATO officials said.
One issue is that Albanian citizens broadly oppose increasing military spending. “The average citizen is mostly thinking about social benefits, hospitals, schools,” said Blerina Abrazhda, the country’s deputy defense minister, adding, “Sometimes they think, ‘Why do we have to prepare for a war that might never happen?’”
Its government is pumping more money into producing ammunition, drones and military uniforms, and is seeking contracts to build Italian ships and buy American helicopters. Last week, Albania approved new budget legislation to increase core defense spending to 2.2 percent of G.D.P.
In Slovenia, officials sought to upgrade roads and rail lines from the Port of Koper on its Adriatic Sea coast to Hungary, a critical logistical supply route. “For Slovenia, this was basic military use,” said Borut Sajovic, who until early June was Slovenia’s defense minister.
Mr. Rutte criticized Slovenian officials in a letter in May for “including projects that do not fall under the agreed definition for core defense expenditure” in its estimates for reaching the 3.5 percent requirement. The letter was first reported by the Slovenian news website 24ur.com.
In a small country like Slovenia, spending 5 percent of G.D.P. on defense “is really big money,” Mr. Sajovic said in an interview. “But we understand that we must do more, and we will — we want to be, and we are, a credible partner in NATO. But we need a little more time.”
Mr. Trump has signaled he is unsympathetic, noting in a social media post last week that the United States still spends more money on defense than any other NATO ally.
“Ridiculous!” Mr. Trump wrote.
