The new NATO chief will face challenges both from external threats and internal sources.

• On Tuesday, Mark Rutte, the former Prime Minister of the Netherlands, will assume the role of General Secretary of NATO, and his leadership abilities will be tested as the alliance faces both external threats and internal weaknesses.
• As a prominent figure in Dutch politics for many years, Rutte served as prime minister from 2010 to 2024 and was widely recognized for his diplomatic skills and ability to bring together diverse groups.

On Tuesday, Mark Rutte, the former Prime Minister of the Netherlands, will assume the role of General Secretary of NATO, where he will face immediate challenges as the alliance grapples with both external threats and internal weaknesses.

As a prominent figure in Dutch politics for many years, Rutte served as prime minister from 2010 to 2024 and was widely recognized for his diplomatic skills and ability to bring together diverse groups.

Rutte, known as "Teflon Mark," has successfully managed political crises at home and will need his skills in managing complex geopolitical relationships to navigate challenging times for NATO.

Besides the ongoing challenge of the Russia-Ukraine war, which continues to escalate with Russia's increasing commitment of troops and funds, the bloc also faces heightened tensions with superpower China and "rogue states" North Korea and Iran.

The Western military alliance is uncertain about the outcome of the upcoming US presidential election, particularly the possibility of a second term for former President Donald Trump, who has frequently criticized NATO members' spending and the alliance's stance towards its primary adversary, Russia.

Rutte announced on Tuesday that he would use his powers of persuasion to persuade NATO's 32 members to increase defense spending, despite it being a persistent issue among member states, despite recent improvements in defense spending among member states, according to data. He also stated that he would work to keep the transatlantic bond in the alliance strong.

Rutte stated during his handover ceremony in Brussels that as Secretary General, he will focus on three primary objectives.

To maintain NATO's strength and ensure effective defense against all threats, we must invest in more forces with better capabilities and faster innovation. However, there is no cost-free alternative.

Rutte stated that his second priority is to enhance support for Ukraine and "bring it closer to NATO" as Europe's security relies on a "strong, independent Ukraine." His third priority is to strengthen alliances within the alliance, particularly with the European Union and countries with similar values, Rutte said. "Our security must be a collective effort," he emphasized.

Rutte stated that he didn't believe there was any immediate risk of a nuclear attack from Russia, despite Putin's repeated warnings that Moscow would use nuclear weapons if its territory was threatened by Western powers supporting Ukraine.

Rutte stated that while Putin's nuclear rhetoric is reckless and irresponsible, there is no imminent threat of nuclear weapons being used.

'Key tests'

Rutte will face numerous challenges as he assumes command of the military alliance, including strengthening Ukraine prior to potential peace negotiations with Russia, increasing defense spending among member states, and managing any consequences from the U.S. election.

Rutte, as NATO secretary-general, will encounter a distinct set of challenges compared to his time as PM, according to Armida van Rij, senior research fellow in the Europe Programme at Chatham House, in an analysis last week.

"Russia is revisionist and assertive externally, while there are challenges to democracy within the alliance and depleted military supplies. The alliance has recently undergone a transformation and developed new regional plans through a new force model, which still require adequate resourcing," she stated.

Oana Lungescu, a distinguished fellow and former NATO spokesperson at the Royal United Services Institute defense and security think tank, stated that Rutte must make a compelling argument not only about figures and percentages, but also about the specific capabilities required to safeguard NATO nations in a perilous world, in an email comment on Monday.

Rewritten: The prospect of another U.S. administration led by former President and Republican candidate Donald Trump poses a potential challenge for Rutte, although he stated on Monday that he would be content to collaborate with either Trump or Vice President Kamala Harris, and that he has amicable relations with both.

Rutte stated that he is not concerned about the upcoming election because he knows both candidates well. He worked with Donald Trump for four years and Trump pushed for increased defense spending, which was achieved as the current spending level is much higher than when Trump took office.

"As vice president, Kamala Harris has a remarkable track record and is highly respected, making it possible for me to collaborate with her effectively," he stated.

Although Rutte has taken a conciliatory approach, it is clear that Trump has had a combative relationship with NATO. In his last term from 2017 to 2021, Trump criticized several member states for not fulfilling their 2014 commitment to spend 2% of their national GDP on defense spending.

During his campaign for re-election, Trump once again unsettled NATO members in February by stating that he would not offer military protection to any member state that had not fulfilled its financial obligations to the alliance and would even "encourage" enemies to take aggressive actions against that country.

The White House was outraged by the comments made by NATO Secretary-General Stoltenberg, who described them as "appalling and unhinged." Stoltenberg responded by stating that any suggestion that NATO was not committed to protecting and defending all allies would jeopardize the security of the entire alliance and put the lives of soldiers and personnel at risk.

Lungescu, a RUSI analyst, described Rutte as a "steady hand" to guide NATO through challenging times. While Rutte may approach Trump with caution, a second term of the Republican could bring unpredictability for NATO.

Rutte, like Stoltenberg, is known as a "Trump whisperer." He is one of the few European politicians who developed a good working relationship with Donald Trump, according to RUSI's Lungescu.

"Nevertheless, a possible second Trump presidency may bring about greater disruption, including reduced U.S. support for Ukraine, greater accommodations towards Russia, and further scrutiny of NATO's worth."