NATO leaders on Wednesday are to formally approve a massive hike in defence spending aimed at financing the alliance's largest rearmament programme since the Cold War, as allies ready for the possibility of a Russian attack on NATO territory.
"This is a quantum leap that is ambitious, historic, and fundamental to securing our future," said NATO Secretary General Mark Rutte in The Hague, the site of this year's summit.
On the second and final day of the meeting in the Dutch city, NATO allies are expected to commit to spending 5% of gross domestic product (GDP) on defence and related expenses by 2035, following persistent pressure from US President Donald Trump to increase their defence budgets.
So far, NATO allies have been obliged to spend at least 2% of their economic output on defence, a goal agreed to in 2014 and only set to be achieved by all member states this year.
Under the new pledge, at least 3.5% of GDP must go to core military expenditure, with an additional 1.5% earmarked for related expenses, including dual-use infrastructure for military purposes.
The additional funds are to provide for a huge expansion of deterrence and defence capacities in the coming years, as Russia's relentless assault on Ukraine highlights the need for stronger protection in the eyes of the trans-Atlantic alliance.
Details of the plans are classified, but Rutte said he expects NATO allies to increase air defence capabilities five-fold and acquire thousands more tanks and armoured vehicles as well as millions of rounds of artillery ammunition.
The new spending target represents a huge challenge for many of the 32 NATO states, and has not come to pass without opposition.
Germany, NATO's second-largest economy after the US, spent around 2.1% of GDP on defence in 2024. Berlin, however, now aims to reach the new target of 3.5% by 2029.
This would require Germany to hire up to 60,000 more soldiers, according to military planners, and spend hundreds of billions of euros for weapons and infrastructure in the coming years.
According to German Chancellor Merz, every additional percentage point of GDP spent on defence means an increase of around €45 billion in military expenditure.
NATO ally Spain, one of the biggest laggards when it comes to defence spending, publicly opposed the plans just days before the summit, saying it had not committed to the new target as it was "not only unreasonable but even counterproductive."
According to Rutte, Madrid says that it can meet its new capability targets - meaning Spain's specific defence capability goals - by spending less than the 3.5% target.
However, Rutte said in a press conference ahead of the summit that "NATO is absolutely convinced" Spain will ultimately have to aim for the higher spending pledge to comply with its capability requirements.
