Europe's decades-long reliance on American military protection has ended, forcing governments across the continent to confront the fiscal reality of defending themselves. Nato leaders gathered in Ankara this week for their annual summit amid deepening uncertainty over whether US forces would actually deploy if a member state came under attack.
Diplomats scrambled ahead of the meeting to prepare a joint statement reaffirming article 5 — that an armed attack on one is an attack on all. The effort reflected growing anxiety that even formal treaty commitments may not guarantee American intervention in the era of Donald Trump.
The summit unfolded against a volatile backdrop. Trump suggested the ceasefire agreement with Iran was "over" following attacks on commercial vessels in the strait of Hormuz, and overnight he threatened Iran that "much worse" could come. During the summit itself, Trump reaffirmed his desire to annex Greenland, criticised peers for not joining Israel and the US's attack on Iran, and requested that the US stop trading with Spain over its reluctance to increase defence spending.
The Spending Reality
Many leaders arrived eager to demonstrate large increases in military expenditure since the previous summit, when member states agreed to raise defence spending to 5% of GDP by 2035. An embarrassing public argument was avoided. Nato secretary general Mark Rutte framed the summit around delivery, emphasising that Europe and Canada were "stepping up" after demands from the US president.
But commitment levels vary dramatically across the continent. Poland and the Baltic states are already spending more than 4% of GDP on defence. Spain has refused to sign up to 3.5%. The disparity reflects fundamentally different threat perceptions — and different levels of fiscal willingness to shoulder the burden America is now shedding.
Ahead of the summit, Britain and 11 other Nato countries committed to a £37bn project over the next decade to build new missile capabilities to protect Europe. Germany may join an effort from the UK, Italy and Japan to build Britain's next generation fighter jet. These are not symbolic gestures. They're expensive, long-term industrial commitments that will reshape national budgets for years.
The Russian Question
Critics of the defence spending surge question whether such massive investment is necessary. Russia has been weakened by the Ukraine war: almost half a million Russian soldiers have died, and the country is facing fuel shortages from Ukrainian drone attacks. Despite threatening language from Vladimir Putin, Moscow is likely several years away from being ready to attack Europe again if it chooses to.
Nato says Russia might be ready for another war by 2030. "But this seems very, very early given that the Ukraine war is still ongoing, thousands of young Russian men have died in the conflict, and lots of materials have been expended," said Dan Sabbagh. "We can't rule it out, but if it were to happen, it would be in many years."
Even so, governments must prepare for the worst. Many European governments have spent the second Trump presidency thinking about how they'd defend themselves if the US didn't come to their aid. So far, Europe's worst fears haven't played out: Trump hasn't forced Ukraine into a peace deal with Russia or teamed up with the Kremlin to reshape the continent. But it remains unclear how the US would respond to Russian aggression against a European country.
Can Europe Stand Alone?
Europe has a population of about 600 million people. Russia has 140 million. "The idea that Europe could not stand on its own two feet against Russia with its economic power and technological advantages is unlikely if there really was a crisis tomorrow," said Sabbagh.
The US has signalled it wants to reduce its numbers in Europe and the amount of fighter jets stationed on the continent by a third, while also redeploying naval and bomber divisions away from the continent. This leaves gaps in the defence architecture.
"Can Europe compensate for that? Of course it can, but it comes at a cost to European taxpayers. The question becomes: what is the level of will among European governments and electorates to do that? As we have seen, that is variable," Sabbagh said.
At least some of the reaction to America's turn away from Europe is emotional. After the cold war ended, the US kept defence spending at a much higher level as part of its ambitions to remain the global superpower. Europe cut military spending and built up its welfare states instead.
"Europe's recognised that you can't get away with leaning on America any more. Europe's been getting away with it for a long time and in a lot of European countries, there's a recognition that it needs to change. The price of deterrence may well be greater than the price that has been previously paid," said Sabbagh.
Even when Trump leaves office, the US position is unlikely to change on its military presence in Europe. There may be more political stability from a future US leader, but there's no going back.
"Europe has just got to do more to stand up for itself. People are less certain what the US would do in a crisis, and they understand they need to be self-reliant. It is a process that will take time. But do they believe that America can't be relied upon at all? I'm not quite sure we're at that stage," he said.
Why This Matters:
The end of America's security guarantee forces European governments to make hard fiscal choices they've avoided for three decades. Defence spending at 5% of GDP means less money for healthcare, pensions, and education — or higher taxes. For countries like Spain that have resisted increases, the question is whether voters will accept austerity to fund militaries they hoped never to use. For Poland and the Baltics, already spending heavily, the burden is becoming unsustainable without broader European burden-sharing. The industrial investments now being made — missile systems, fighter jets, naval capacity — will lock in defence budgets for a generation. Europe's peace dividend is over. The bill for deterrence is coming due, and national governments must now explain to their citizens why welfare expansion has given way to rearmament. Democratic accountability requires honest conversation about these trade-offs, not Brussels-led spending mandates that bypass national parliaments.