When leaders from 32 NATO countries come together in Washington, D.C., this week, they will celebrate the 75th anniversary of the alliance. "The most successful and strongest alliance in history," as outgoing Secretary-General Jens Stoltenberg characterized it in an interview with DW.

Since Russia's invasion of Ukraine, NATO has indeed been reinvigorated. It has firmly responded to the war on its doorstep. Allies have gradually expanded their military and financial support for Ukraine, even though Kyiv is not a member of the alliance.

500,000 combat-ready troops

NATO has drafted new plans for its own defense and deployed more troops to the front-line states close to Russia, with 500,000 soldiers now ready for combat in Europe. It has welcomed new members, Sweden and Finland — two strong democracies with modern armed forces.

NATO nations now invest more in defense. The number of countries spending at least 2% of their gross domestic product (GDP) on defense has grown from nine in 2021 to 23 — "a record number," according to Stoltenberg.

Is Joe Biden up to the job?

The summit in Washington, DC, is therefore meant to send a signal of strength and unity. But the gathering is at risk of being overshadowed by US domestic politics. With President Joe Biden facing questions whether he is still up to the job and able to win re-election, many in Europe fear a second Donald Trump presidency has become more likely.

During his term in office, Trump repeatedly railed against the alliance and threatened to make Europeans pay for US protection. Recently, on the campaign trail, he went as far as suggesting Russia could "do whatever the hell they want" to NATO members who didn't meet defense spending targets.

Transatlantic bond at risk

Worries about repercussions should there be a second Trump presidency have been long played down at NATO headquarters and in capitals across Europe, with diplomats arguing that no-one can stop elections in a democracy and that political changes are part of life across the alliance.

"The Americans know very well the value of the NATO alliance," German Defense Minister Boris Pistorius told DW in an interview earlier this year. "Everyone knows that anyone who messes with the Transatlantic bond puts their own geopolitical and strategic interests at risk."

Efforts to ‘Trump-proof' NATO

But even if Trump is unlikely to pull out of NATO altogether, as recent reports indicate, many expect him to substantially reduce America's security role in Europe. For the NATO alliance, which has been dominated by the massive military power of the US, that will have significant consequents.

In recent months, Secretary-General Stoltenberg has led efforts at NATO to push the Europeans toward a security architecture more to Trump's liking. The growing number of countries living up to their promise to spend more on defense is part of those efforts.

Self-congratulatory Europeans?

Stoltenberg and many Europeans are "very self-congratulatory" on that matter, Majda Ruge, a senior policy fellow with the European Council on Foreign Relations, told DW. She pointed out that there are still nine countries, including Canada, Italy and Spain, that spend less than two percent of their GDP on defense. "If you are a super small country with a tiny GDP and spend 3.5 percent, that is still not going to make a difference on the battlefield," Ruge explained. 

Ahead of the summit in Washington DC, Polish President Andrzej Duda — an ardent Trump admirer — has called on NATO countries to agree on a new spending target of 3 percent of GDP on defense. Ian Lesser, distinguished fellow at the German Marshall Fund, a transatlantic think tank, told DW he doesn't expect the burden-sharing argument to disappear quickly, regardless of who wins the race to the White House.

Inevitable gap?

"The adjustments required in terms of budgets and planning and strategy and public acceptance are not going to be made overnight," Ian Lesser said, He cited building a stronger defense industrial base in Europe — an effort that could take decades — as an example. "There is an inevitable gap between what is desirable and what has already been done."

A gap that could notably also affect Western support for Kyiv. At their summit in Washington, NATO leaders will greenlight a plan allowing NATO to lead the coordination of security aid and training for Ukraine.

A new command to coordinate Ukraine aid

According to Jens Stoltenberg, this will put support for Ukraine "on a firmer footing for years to come," with a command in Wiesbaden, Germany, and nearly 700 personnel from allies and partners.

The plan, created after significant delays in deliveries of US weapons to Kyiv, has been described as a way to 'Trump-proof' NATO backing for Ukraine among fears that Trump could stop all aid to Ukraine if he will be elected again.

No membership invitation for Ukraine

It is a "way of natural evolution" to put NATO "closer to the center of gravity" when it comes to military support for Ukraine, Ian Lesser, the foreign policy expert at the German Marshall Fund, said. He describes the initiative as an alternative to dealing with the question of NATO membership of Ukraine, which is still highly controversial inside the alliance.

But in terms of military aid for Kyiv, the US is still "an extremely important actor," Lesser said. "Taken together, European allies have done perhaps roughly as much as the United States has done in terms of military support to Ukraine."

Political turbulences in Europe

A crucial question is not only whether Europeans will be capable, but also whether they will be willing to fill the void should the US withdraw or drastically reduce its aid for Ukraine. Ruge describes a divided Europe as one of the biggest risks in the future.

Many European leaders seem weak at the moment. French President Macron will arrive at the NATO summit fresh off a second round of contested parliamentary elections. German Chancellor Scholz faces a growing far-right in his country. And British Prime Minister Keir Starmer is new in office.

"Not only is Europe concerned about the outcome of the US election and its potential effects on NATO, but also how that outcome might interact with political developments in Europe," Ian Lesser at the German Marshall Fund said. In a way, he said, there is a general mood of political uncertainty on both sides of the Atlantic.

Edited by: Andreas Illmer