Mark Rutte announced in July 2023 that he was resigning as prime minister of the Netherlands and "retiring from politics" after his government coalition collapsed over differences in migration policy.

By October of that year, however, Rutte had seemingly forgotten all about his vow to leave politics, signalling his interest in succeeding NATO Secretary-General Jens Stoltenberg, who had announced he would finally leave the post in September 2024 after a decade at the helm of the alliance.

For months, Rutte ran a discreet one-man campaign to win over NATO leaders, most of whom he already knew from more than 13 years as Dutch prime minister, and from working with various international bodies. The trained historian was the favored candidate of US President Joe Biden, as well as of most European leaders.

One diplomat told DW that Rutte is seen as "Mr. No" on the European Union side of town because he has rejected ambitious reform plans and ideas floated by French President Emmanuel Macron. Rutte does, however, get on well with German Chancellor Olaf Scholz.

He is also on good terms with Italy's right-wing populist prime minister, Giorgia Meloni. Together, Rutte and Meloni have suggested processing asylum applications outside the EU in third-party states.

Hungary holds out

But winning over Hungary's right-wing nationalist Prime Minister Viktor Orban, with whom he is not on the best of terms, took a bit longer. Rutte had to promise Orban that Hungary would never have to participate in activities supporting Ukraine outside of NATO territory, as long as Rutte led the alliance. Orban, who maintains friendly ties with Russia, has also ruled out arms deliveries to Ukraine.

Rutte's liberal politics and Orban's illiberal outlook often put them at loggerheads in their dealings within the EU. When Hungary adopted an anti-LGBTQ+ law in 2021, Rutte told Orban he was free to leave the bloc if he disagreed with its policies.

Rutte's famed ability to weather political adversity has earned him the nickname "Teflon Mark," and that may come in handy should Donald Trump return to the White House and set his sights on criticizing NATO once again. Despite this tendency, Rutte and Trump developed a surprisingly positive relationship during Trump's first term as US president from 2017 to 2021, with Trump even calling Rutte a "friend." But Rutte, as the leader of an historic trading nation, fiercely opposed Trump's protectionist economic policy.

Rutte supports arming Ukraine

Unlike Trump, Rutte is a staunch supporter of Ukraine and has overseen robust weapons deliveries to Kyiv, including Dutch howitzers and F-16s.

The Dutch army itself, however, was underfunded throughout Rutte's years in power. This year will be the first time the Netherlands will spend 2% of its GDP on defense, in line with NATO spending targets.

Rutte has long been critical of Russian President Vladimir Putin, not least because Russia is widely seen as at least partly responsible for the downing of flight MH-17 over eastern Ukraine in 2014. Almost 300 people, most of them Dutch nationals, died when the Malaysia Airlines plane en route from Amsterdam to Kuala Lumpur was brought down by what international investigators concluded was a Russian-made missile fired from separatist-occupied territory in eastern Ukraine.

Creating consensus within NATO

Rutte is experienced at managing coalitions in the Netherlands, but now he has 32 parties to rope into the consensus required for all NATO decisions.

Former NATO spokesperson Oana Lungescu, the longest-serving person in that role, believes this will be Rutte's biggest challenge. "The secretary-general of NATO has to be not just a secretary, but also a general, in political terms, of course," she told DW. 

"He has to show the political leadership needed to push forward the alliance, because achieving consensus can take time. It can be messy, it can be frustrating but it's important to show political direction and to show progress." She emphasized that Rutte's long experience holding fractious Dutch coalition governments together will serve him well going forward.

But friends of Rutte have shared in various interviews that one of his other challenges may be adapting to life in the NATO spotlight. As Dutch prime minister, he famously cycled from his modest home in The Hague to his office. In Brussels, he may have to use a driver to get to NATO headquarters, but Lungescu expects Rutte will find time to decompress the same way his two immediate predecessors have.

"Jens Stoltenberg and Anders Fogh Rasmussen before him were also keen cyclists," she said, "so you could sometimes see them ... in the woods around Brussels or elsewhere, taking the opportunity to bike or to run or to exercise whenever they could."

But Lungescu noted, being NATO chief will mean having to submit to certain unavoidable necessities of the high-profile position.

"It's going to be an interesting tradeoff between security and openness to others," she explained. "In the current situation, I think we need to have both."

Alexandra von Nahmen also contributed to this report. 

Edited by: Helen Whittle

An original version of this article was originally written in German and published on June 20, 2024. It was updated on September 29, 2024 to reflect Rutte's October 1 installation as the new NATO chief.