Much of the attention at this week's NATO summit in The Hague will likely be on US President Donald Trump, following the US strikes on Iran's nuclear sites over the weekend.

But ramping up defense spending, a major demand by Trump and his administration since day one, will also be in the spotlight. This goal has become potentially acceptable to almost all NATO countries thanks to the persuasive power of Secretary-General Mark Rutte, particularly after Germany, the biggest European economy,  threw its weight behind it.

Officials at NATO told DW that it's about giving Trump a win but also "about rebalancing in the alliance," as one senior diplomat put it, stressing that if that's achieved, the summit would be a resounding success.

Lessons from the G7 in Canada

"Hopefully, Trump is not going to leave early like he did from the recent G7 meeting in Canada," Jamie Shea, a former NATO official, told DW. This worst-case scenario is a big concern for some NATO allies and something they want to avoid at any price.

Shea said he thinks "it's important for Trump to be there to learn about all of the good things that NATO is doing at the moment, which help America's security and not just Europe's security."

The goal of spending 5% of GDP on defense, expected to be approved at the summit in The Hague this week, is highly ambitious, and has the potential to transform societies in Europe. In many EU countries, social justice and economic stability were the clear priorities for national governments for decades; in the future they might concentrate on strengthening military power and becoming more independent from the United States.

This scenario has led to growing resistance in some parts of Europe. Spain had been against the measure, but ultimately dropped its opposition on Sunday after a deal was reached for it to be exempt.

How to deter Russia from attacking NATO territory

Asked about how he would explain his plan to citizens in Europe who are against social cuts in favor of new weapons, Rutte recently said leaders need to act now because "otherwise, four or five years from now, we are really under threat and then you have to get your Russian language course or go to New Zealand."

Rutte's idea is to cut the cake into two pieces and to allocate 3.5% of GDP to core defense needs and 1.5% to security-related investments. These investments include building broader roads and bridges that could carry heavy weaponry but also upgrades on cybersecurity, measures against hybrid attacks, civil protection and aid for Ukraine.

Members of the alliance will try to factor in what they are already spending, for instance, on infrastructure, diplomats at NATO acknowledge. But they also stress that the fact that allies were able to agree on the exact definition of the 1.5% target is already a significant success.

Spain wants an exemption

The biggest challenge is getting everyone on board with the 3.5% target for core military spending. Spain, which has the lowest military spending in the alliance, signaled prior to the summit that it wanted a carve-out.

Other nations, like Italy, are demanding more time than the proposed seven years to meet the obligation. Many NATO members are ready to spend more but refuse to commit to yearly plans — a kind of control mechanism — also proposed by Rutte.

In the end, it comes down to NATO's credibility, Lithuania's former foreign minister, Gabrielius Landsbergis, told DW. The alliance "is moving in the right direction," he said. But like many representatives of the countries on NATO's Eastern flank in proximity to Russia, he warns against not being serious about fulfilling the new spending pledge. "What if it is just to have a nice summit and everyone leaves happy, and then nothing really happens?"

A disappointing summit for Ukraine?

In addition, many Europeans are unhappy about the apparent lack of any ambition when it comes to Ukraine. While Ukrainian President Volodymyr Zelenskyy has been invited to the summit, his aspirations to join NATO are unlikely to take center stage at the summit or be prominently featured in the final declaration

"Clearly, the United States in particular has wanted to play it down," explained former NATO official Shea. "So, for Ukraine, it is going to be a rather disappointing NATO summit."

There will be a sentence or two as a reference to Russia as a threat in the final document, NATO sources told DW, but no new tough language, given the ongoing US attempts to get both countries to the negotiating table.  

It's all about Russia

Kristine Berzina, a NATO expert with the German Marshall Fund think tank, said it's important to look at the bigger picture.

"We get so obsessed with the little declarations and paragraphs about such and such," she told DW. What really matters is that "NATO is a strong political alliance and the people at the table believe in each other." That is what she expects to be the summit's strong message.

"Of course, it is about Russia. Talking about the ambitious new steps they're going to take is a signal to Russia," Berzina said.

Still, the summit declaration is expected to be "short and crisp," as one diplomat put it, and the event is deliberately planned as a brief exchange not to bore Trump, who's known for not being a fan of long speeches by others, and of multilateral organizations in general.

A recipe to keep Trump happy

The big risk is that, with the escalation of the conflict in the Middle East, Trump may not travel to The Hague at all, according to media reports in the US. At NATO HQ in Brussels, diplomats have so far said they do not have any indication that Trump won't be there.

So, is the NATO summit just about pleasing Trump, as the program, including a dinner with the Dutch king, an invitation to play golf in the Netherlands and the expected big spending splash, indicates?

In the end, it's about the Europeans, said Shea. "The 5% of GDP for defense spending is to deter Russia, to keep Europe and NATO citizens safe, sleeping soundly in their beds at night." But he also admitted that "provided the decision on the 5% is taken, Trump should go back to Washington a happy man."

Edited by: Rob Mudge

Update, June 23, 2025: This article has been updated with the latest on Iran and the 5% defense spending goal.