Nato leaders have agreed on a massive hike in defence spending after pressure from US President Donald Trump, and expressed their 鈥渋ronclad commitment鈥 to come to each other鈥檚 aid if attacked.
The 32 leaders endorsed a final summit statement saying: 鈥淎llies commit to invest 5% of GDP annually on core defence requirements as well as defence- and security-related spending by 2035 to ensure our individual and collective obligations.鈥
Spain had already officially announced that it cannot meet the target, and others have voiced reservations, but the investment pledge includes a review of spending in 2029 to monitor progress and reassess the security threat posed by Russia.
The leaders also underlined their 鈥渋ronclad commitment鈥 to Nato鈥檚 collective security guarantee 鈥 鈥渢hat an attack on one is an attack on all鈥.
Ahead of the summit, Mr Trump had again raised doubts over whether the United States would defend its allies.
The show of unity vindicated Nato secretary general Mark Rutte鈥檚 billing of the summit as 鈥渢ransformational鈥, even though it papered over divisions.
The spending pledge sets European allies and Canada on a steep path towards significant military investment.
The spending hike requires each country to spend billions of dollars.
It comes as the United States 鈥 Nato鈥檚 biggest-spending member 鈥 shifts its attention away from Europe to focus on security priorities elsewhere, notably in the Middle East and Indo-Pacific.
But ahead of the meeting, Spain announced that it would not be able to reach the target by the new 2035 deadline, calling it 鈥渦nreasonable鈥.
Belgium signalled that it would not get there either, and Slovakia said it reserves the right to decide its own defence spending.
Many European countries face major economic challenges, and Mr Trump鈥檚 global tariff war could make it even harder for America鈥檚 allies to reach their targets.
Some countries are already squeezing welfare and foreign aid spending to channel extra funds into their military budgets.
On Tuesday, Mr Trump complained that 鈥渢here鈥檚 a problem with Spain. Spain is not agreeing, which is very unfair to the rest of them, frankly鈥.
He has also criticised Canada as 鈥渁 low payer鈥.
In 2018, a Nato summit during Mr Trump鈥檚 first term unravelled due to a dispute over defence spending.
But Mr Rutte conceded that 鈥渢hese are difficult decisions. Let鈥檚 be honest. I mean, politicians have to make choices in scarcity. And this is not easy鈥.
But he said: 鈥済iven the threat from the Russians, given the international security situation, there is no alternative鈥.
Other countries closer to the borders of Russia and Ukraine 鈥 Poland, the three Baltic states and Nordic countries 鈥 have committed to the goal, as have Nato鈥檚 European heavyweights Britain, France, Germany and the Netherlands.
鈥淭his is a big win, I think, for both President Trump and I think it鈥檚 also a big win for Europe,鈥 Finnish President Alexander Stubb told reporters.
鈥淲e鈥檙e witnessing the birth of a new Nato, which means a more balanced Nato.鈥
He said it would take nations 鈥渂ack to the defence expenditure levels of the Cold War鈥.
Nato countries started to cut their military budgets in safer times after the Berlin Wall collapsed in 1989.
In a fresh take on Mr Trump鈥檚 Maga movement, Lithuanian President Gitanas Nauseda said: 鈥淲e should choose a motto, 鈥榤ake Nato great again鈥.鈥
After Russia鈥檚 full-scale invasion of Ukraine in 2022, the Nato allies agreed to make 2% of GDP the minimum spending level.
Last year, 22 countries were expected to hit that target, up from just three a decade ago.
In The Hague, the allies endorsed a major revamp of their spending targets.
They upped the ante for what Nato calls 鈥渃ore defence spending鈥 to 3.5%, while changing how it is counted to include providing military support to Ukraine.
To hit Mr Trump鈥檚 5% demand, the deal set a second target of 1.5% of GDP for a broader range of defence-related spending, such as improving roads, bridges, ports and airfields so that armies can deploy more quickly, countering cyber and hybrid attack measures, or preparing societies to deal with future conflicts.
Progress will be reviewed in 2029, after the next US presidential election.
鈥淭his declaration is historic. We are 32 allies supporting that ambition, which is huge,鈥 said Norwegian Prime Minister Jonas Gahr Store.
鈥淲e have been struggling to get above 2% and now we said 3.5%, which is necessary in order to reach our capabilities.鈥
Earlier this month, Nato agreed individual purchasing targets for nations to stock up on weapons and military equipment to better defend Europe, the Arctic and the North Atlantic, as part of the US push to ramp up security spending.
Extra funds will also be needed should the Trump administration announce a draw-down of forces in Europe, where around 84,000 US troops are based, leaving European allies to plug any security gaps.
The Pentagon is expected to announce its intentions in coming months.
Beyond Mr Trump鈥檚 demands, European allies and Canada have steeply ramped up defence spending out of concern about the threat posed by Russia.
Several countries are concerned that Russia could carry out an attack on Nato territory by the end of the decade.
Hungary is not one of them, though.
鈥淚 think Russia is not strong enough to represent a real threat to us. We are far stronger,鈥 said Hungarian Prime Minister Viktor Orban, fielding questions from reporters, leaning back with his hands thrust into his pockets.
Mr Orban is considered Russian President Vladimir Putin鈥檚 closest ally in Europe.