‘If you want peace, prepare for war,’ warns former NATO secretary general

Read time: 4 mins

In brief…

• Jens Stoltenberg tells Lewis Goodall he believes Russia is unlikely to invade Europe, but says the UK government is right to ready itself for war if it hopes to achieve peace.
• The former NATO secretary general says he once believed Vladimir Putin wanted to bring positive change to Russia, but may have been wrong about him all along.
• He says he was “concerned” about Donald Trump’s return to power, but says while the two have had disagreements, believes the US president’s “clear message” works in some areas.

What’s the story?

Jens Stoltenberg probably knows more about Russian leader Vladimir Putin than most European politicians.

Now Norway's Minister of Finance, Stoltenberg has served as its Prime Minister on two separate occasions and was the secretary general of NATO when Putin invaded Ukraine in February 2022.

Stoltenberg tells Lewis Goodall that the Russian leader today is a different man to the one he first encountered in 2000.

"He was a newly elected president of Russia, I was a newly elected prime minister of Norway," he says.

"We met, had a good meeting, and I felt that he was a man that wanted to change Russia and actually develop a better relationship with the West."

He was among many European politicians to feel “optimistic” about Russia’s future under Putin at the time.

“Maybe it was wrong already then, but I think it's more likely that he gradually changed,” Stoltenberg adds.

“He realised, after some years, that democracy, rule of law and open societies, was a threat to his power base, and therefore he started to become more authoritarian.”

Putin invaded Ukraine in February 2022, with hundreds of thousands of casualties reported on both sides of the conflict.

Stoltenberg says the man he saw then was very different to who he had first met, and wanted to establish a world order where superpowers have tight control over their smaller neighbours.

'Putin has achieved the opposite of his goals in Ukraine'

One of Putin's main aims in attempting to seize  Ukraine was to prevent it from joining NATO – which Stoltenberg says has backfired for the Russian leader.

"The reality is that Ukraine is closer to NATO than ever before," he says.

Ukraine is not a member, but has been supported by NATO throughout the current war.

"The outcome is the exact opposite of what Russia wanted."

Finland joined NATO in April 2023, a year after Putin first invaded Ukraine, joining Norway, and doubling the border between Russia and NATO states.

Norway was one of the founding members of NATO, which helped establish the international organisation in 1949.

Volodymyr Zelensky has said he is willing to "trade" his role as president for a Ukraine NATO membership.

Stoltenberg describes Zelensky as a "great leader", and says his handling of the war has exceeded expectations.

He adds, however, that he refused Zelensky's request, days after Putin's forces invaded, to close the airspace over Russia as NATO did not want to have to shoot down Russian fighter planes, and engage in direct conflict.

'Donald Trump's clear message is having an impact on the world'

Donald Trump has made various claims about what would, and what would not, have happened if he had been president when Russia first invaded Ukraine – and Stoltenberg refuses to speculate on that.

He does, however, credit the president with selling anti-tank Javelin missiles to Ukraine in 2017, but says he felt "concerned" when he was re-elected in 2024, having developed an anti-NATO stance.

But he says that as Trump's second term in office has unfolded, his anger appears to be directed more at NATO members paying smaller amounts than the US, than at the organisation itself.

"He has a different style and is sometimes more direct," Stoltenberg says.

"We disagree on issues like trade and tariffs or climate change, but as Secretary General of NATO, we were focused on the issues that matter for NATO."

Despite their disagreements, Stoltenberg says Trump's "clear message" is having an impact – not least in forcing other NATO countries – including the UK – to increase their contributions.

Should the UK and Europe plan for war with Russia?

In June 2025, the UK government said the country must "actively prepare" for a military threat – naming Russia as the biggest threat to peace.

Stoltenberg believes a war between Europe and Russia is “unlikely” – but believes we will see increased cyber attacks, sabotage attempts and airspace violations in coming years.

He says the more important question we should be asking is how to minimise the threat of war, not ponder over when it might be coming – but agrees the UK is right to ready itself.

"I strongly believe that we need to strengthen our deterrence and our defence, invest more in modern capabilities to do what NATO has agreed to do, and that is to significantly ramp up our military capabilities," he adds.

"If you want peace, prepare for war."

Jens Stoltenberg's book, On My Watch: Leading NATO in a Time of War, is out now.

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