Jens Stoltenberg, who has led NATO since 2014, is stepping down in favor of former Dutch Prime Minister Mark Rutte.
A series of events are planned for today in Brussels to mark the change at the head of NATO.
After a symbolic handshake and wreath-laying at NATO headquarters, they will meet with the bloc’s ambassadors to the North Atlantic Council for Rutte’s official appointment.
Stoltenberg took over leadership of the military alliance the same year Russia annexed Crimea. Only the mandate of Dutch diplomat Jozef Luns, who led NATO for 12 years, exceeds Stoltenberg’s.
The long-serving Dutch prime minister takes office as Russia’s invasion of Ukraine approaches the 1,000-day mark.
With Russian forces advancing in eastern Ukraine, it will be a key part of his job to shore up support for Kiev among Western allies as conflict fatigue mounts.
Among the bloc’s members, there is also concern about the US presidential election in November.
Given that the US is NATO’s most powerful member, a victory by former President Donald Trump could shake up the alliance as it did in his first term, when he pressured members to increase defense spending and cast doubt on the bloc’s core principle of mutual security.
During more than ten years at the head of NATO, Stoltenberg was praised for his calm leadership of the sometimes divided Alliance.
The Norwegian helped keep US President Donald Trump from turning his back on him, backed Ukraine by ensuring NATO was not drawn directly into war with Russia, and launched a reform of the alliance’s defense capabilities to confront Moscow.
“The allies were looking for someone who has many qualities like Stoltenberg and who will continue in the same direction: a prime minister, with good connections, long experience, a good address book, who knew Trump well,” said Jamie Shaw, a former senior NATO official.
Rutte, a favorite of key powers such as the USA, Britain, France and Germany, met all these conditions.