US President Donald Trump’s outbursts against NATO allies, claiming “we spend all the money,” left a defining mark, particularly during his second presidential term.

At the 2025 summit in The Hague, member states pledged to allocate 5% of their annual GDP to defense by 2035. This marked a monumental leap from the 2% commitment made at the 2014 Wales summit.

This 5% commitment encompasses two primary categories of defense investment. The first is “core defense requirements”: allies agreed to dedicate at least 3.5% of their GDP to meeting baseline defense needs and fulfilling NATO Capability Targets, based on the agreed definition of NATO defense expenditure.

The second is “defense and security-related expenditure”: under this heading, member states will allocate up to 1.5% of their GDP to broader defense and security-related investments, such as protecting critical infrastructure, defending networks, ensuring civil preparedness and resilience, and strengthening innovation and the defense industrial base.

According to NATO’s own figures, European allies and Canada increased their defense spending by over $90 billion in 2025, representing an approximate 20% increase compared to 2024.

Official NATO reporting also indicates that European nations and Canada have steadily increased their collective defense investments over the past decade: rising from 1.4% of their total GDP in 2014 to 2.3% in 2025, culminating in a total investment of over $571 billion in defense spending this year.

According to NATO statistics, the United States consistently spends upwards of 3.5% to 4% of its GDP on defense. In absolute terms, of course, no single NATO power can match the expenditure of the American military.

Yet the issue of “burden-sharing,” which became highly visible during the Trump era, is not new. Setting aside the debates during the detente periods of the Cold War, American defense spending and public debt began to swell significantly in the late 1990s, spinning out of control in the wake of the invasions of Afghanistan and Iraq. Coupled with the rise of China and the US declaration of a military pivot to Asia, this ignited an open debate on how the “security architecture” of the Euro-Atlantic axis would transform.

Bush’s call

Attending the 2008 NATO summit in Romania, then-US President George W. Bush laid out a lengthy list of threats, primarily featuring Iraq and Afghanistan but also spanning Iran and Northeast Asia, before outlining the measures required to shield Europe from “missile threats.”

Bush stated:

“To build a strong NATO Alliance, a strong European defense capability is also essential. Therefore, at this summit, I will encourage our European partners to increase their defense investments to support both NATO and EU operations. America believes that if Europeans invest in their own defense, we will be stronger and more capable when we act together.”

Recently, an article written on behalf of the George W. Bush Presidential Center for the Ankara summit revisited the issue of “burden-sharing.” Authored by Elizabeth Kennedy Trudeau, a former State Department official, the piece references past debates, noting: “Today, it is abundantly clear that the endless debate over burden-sharing is no longer a theoretical issue, and that is also how the public perceives it.”

According to Trudeau, “Russia’s ongoing aggression against Ukraine,” “instability in the Middle East,” “China’s growing ambitions,” and emerging threat domains such as cyber threats, disinformation, and vulnerable supply chains have radically altered the geopolitical landscape. Consequently, NATO must adapt to this new reality.

Pointing out that European allies have increased their defense spending, the author welcomes the Continent’s steps toward assuming greater responsibility for “collective defense,” asserting: “This is not because the United States is pulling away from NATO; rather, a stronger Europe makes this powerful alliance even stronger.”

A sharp rebuke from Obama’s Defense Secretary Gates

However, the most scathing critique directed at the Old Continent from the US came during the presidency of Barack Obama.

In a university address, then-Defense Secretary Robert Gates argued that Europeans’ reluctance to employ military force was “limiting NATO’s ability to conduct effective military operations.”

At the time, redrafting the NATO alliance’s core strategic concept was on the agenda. In his speech, Gates called for sweeping reforms within the organization. He remarked that NATO’s success in preventing conflicts from erupting in post-WWII Europe had inadvertently fostered a new set of concerns:

“The demilitarization of Europe—where large swaths of the public and political class are opposed to military force and the risks that go with it—has gone from being a blessing in the 20th century to an obstacle to achieving real security and lasting peace in the 21st.”

Gates warned that unless NATO members maintained robust militaries and made the necessary budgetary commitments to modernize their forces, Europe would remain vulnerable to threats.

The Secretary stated, “Real or perceived weakness does not merely invite miscalculation and aggression; on a more fundamental level, the resulting funding and capability shortfalls make it difficult to act and fight together to confront common threats.”

Defining NATO as “a military alliance with real-world, life-and-death obligations,” Gates noted that the ongoing effort to “rethink and reshape” the alliance’s strategic mission came at a critical juncture.

“Currently, the alliance faces very serious, long-term, systemic problems. NATO’s budget crisis is but one example, and it is a symptom of deeper issues within NATO regarding how threat perception, requirement determination, prioritization, and resource allocation are handled.”

In a speech in Brussels the following year, Gates also criticized Germany for not participating in the NATO airstrikes aimed at toppling Muammar Gaddafi in Libya. He warned that patience was wearing thin in the US Congress toward Europeans who were reluctant to stand “on their own feet”:

“The blunt reality is that there will be dwindling appetite and patience in the U.S. Congress—and in the broader American body politic—to expend increasingly precious funds on behalf of nations that are apparently unwilling to devote the necessary resources or make the necessary changes to be serious and capable partners in their own defense.”

It is worth recalling that an NBC report at the time remarked, “This assessment could prompt Europeans to question the future of their defense relationship with the US, upon which they have relied for much of their security over the past six decades.”

Moreover, the controversy erupted immediately after the withdrawal of an American combat brigade from Europe as part of a significant reduction in US troop levels on the continent.

During the Q&A session following his address, Gates also remarked that his generation’s “emotional and historical attachment” to NATO was “fading over time.”

Without naming them, Gates delivered a sharp critique of “countries apparently willing and eager for American taxpayers to shoulder the growing security burden left by cuts in European defense budgets.”

Warnings from Hillary Clinton

A similar theme was voiced by then-Secretary of State Hillary Clinton. Clinton observed, “NATO is turning into a two-tiered alliance, where the proportion of member states willing and able to pay for and bear the burden of collective defense is steadily shrinking.”

Intriguingly, this assessment closely mirrored remarks by former NATO Secretary General Anders Fogh Rasmussen at an annual national conference in Norway, where he noted that “the United States accounts for two-thirds of NATO’s defense spending.”

In her 2010 “Future of NATO” speech, Clinton stated:

“You will also hear this from Secretary Gates: despite historical and entirely understandable reasons why European countries have not yet committed to a level of per capita defense spending—not to the level we would like to see you reach, which is our level, but higher than where most of you are now—we believe this is a subject that must be discussed honestly. Because many of the infrastructure challenges we will face in the confrontation of these new threats—such as energy security or cybersecurity—will require member states to invest more so that we can network through NATO. It will be less about NATO doing the job than about member states coordinating and collaborating with their investments.”

Divergence in Europe

The impact of the 5% spending floor set at the Hague summit varies significantly across European states.

Reuters points out that two distinct groups have emerged since the decision: the first comprises Germany and mostly Nordic and Eastern European countries, which possess the fiscal flexibility to scale up spending; the second consists of several major actors struggling to achieve the same.

Guntram Wolff, a researcher at the economic think tank Bruegel, notes of Europe’s three largest economies after Germany: “The UK, for instance, cannot manage this. Neither can France, nor Italy.”

According to a draft budget obtained by Reuters ahead of Monday’s cabinet meeting, Germany will leverage a rule change exempting defense items from strict borrowing limits, doubling its spending to over 200 billion euros ($228.38 billion) between now and 2030.

Poland, Lithuania, and Estonia—countries where the perception of the Russian threat is most acute—have already made significant strides toward meeting the new targets. Warsaw, in particular, allocated 4.3% of its GDP to defense last year.

On the other hand, this initiative faces steep political and financial hurdles. Last week, Britain announced a plan for £15 billion in additional defense spending, to be partially funded by cuts in other areas.

However, it has emerged that a third of this sum remains unfunded, presenting an early budgetary headache for the presumptive new prime minister, Andy Burnham.

Meanwhile, Italian Prime Minister Giorgia Meloni is expected to announce at the summit that Rome will increase its core and non-core defense spending to 2.8% of GDP in 2026, despite carrying one of Europe’s heaviest debt burdens.

However, because rising military expenditures are unpopular with many voters ahead of next year’s general election, most of the increase will be covered by domestic security spending, such as policing duties.

France, through detailed plans unveiled in April, aims to increase its defense spending from the current level of around 2% to 2.5% of GDP by the end of the decade, all while trying to bring its overall budget deficit into alignment with Eurozone rules. With presidential elections on the horizon, how the Macron administration will generate this surplus remains a matter of curiosity.

The Spanish government, meanwhile, is not expected to waver in its commitment to cap defense spending at no more than 2.1% of GDP. Its plan is to redirect new resources largely toward technologies with civilian applications.

Furthermore, some countries appear to inspire little confidence at NATO headquarters: NATO officials have questioned claims by the Czech Republic, Slovenia, and Albania that they have met the old alliance target of 2% of GDP, requesting that these nations revise and resubmit their spending figures.