NATO is a transatlantic military alliance. Its first head, Hastings "Pug" Ismay, reputedly said its purpose was to "keep the Soviet Union out, the Americans in and the Germans down". About 80,000 American troops are stationed in Europe. At the summit in The Hague on June 24th–25th 2025, allies agreed on a new spending target: 3.5% of GDP on "core military requirements", with an additional 1.5% on defence-related spending such as infrastructure and industrial capacity. Donald Trump has called for 5%. Central and eastern European states pushed for a 2032 deadline; others, such as Slovakia, wanted 2035. Spain was the only holdout on the target; it was expected to fold. Germany has signalled it will sign up. Among major member economies in 2024, Italy spent an estimated 1.49% of GDP on defence, Spain 1.28% and Canada 1.37%. The Baltic states and Poland plan to spend 5% of GDP on defence by 2026. Twenty-three members now meet the twin targets of spending 2% of GDP on defence and 20% of defence budgets on equipment.
Turkey has the alliance's largest army in Europe after Ukraine, with some 400,000 active troops, but has been a disruptive member—holding up Finland's and Sweden's accession and blocking defence plans for Poland and the Baltics.
Donald Trump's December 2025 National Security Strategy calls for halting NATO's expansion. It argues that Europeans' "lack of self-confidence"—not the invasion of Ukraine—causes them to see Russia as an "existential threat", and says America's "core interest" is to "negotiate an expeditious cessation of hostilities in Ukraine".
Donald Trump's pursuit of Greenland in January 2026 brought transatlantic ties to their worst point since the Suez crisis 70 years earlier. Trump imposed tariffs on eight NATO members that had sent troops to the island, threatening escalation if Greenland was not in American hands by June 1st. The European Parliament put on hold the Turnberry Agreement, a trade deal under which the EU accepted a 15% tariff rate without reciprocating, meaning European tariffs on about €93bn ($108bn) of American goods were set to take effect. Emmanuel Macron suggested the EU invoke its anti-coercion instrument (ACI), a mechanism never before used that would have allowed retaliation beyond matching tariffs—from cancelling banking licences to restricting exports of chip-making equipment (a business in which ASML has a monopoly). Mark Rutte brokered "the framework of a future deal" with Trump on January 21st, defusing the immediate crisis.
America deploys about 100 B61 tactical nuclear gravity bombs at six bases in five European countries for NATO's nuclear-sharing mission, in which European air forces practise delivering the weapons. Russia has 1,000–2,000 deployed tactical nuclear weapons, an order of magnitude more than NATO.
At The Hague summit in June 2025, Britain announced it was joining the nuclear-sharing mission, planning to buy F-35A jets capable of carrying American nuclear bombs. It is one of the biggest shifts in the alliance's nuclear posture for decades; the Royal Air Force gave up nuclear bombs more than 25 years ago. A former Pentagon nuclear official called enhanced British participation "the single greatest augmentation in NATO nuclear deterrence possible at the moment."
On the night of September 9th–10th 2025, 19 Russian drones breached Poland's airspace—the most serious incursion into NATO territory since the alliance's founding in 1949. Polish and Dutch fighter jets shot down some of them; one fell 300km inside Poland. Poland invoked Article 4, triggering consultation with allies. It was only the eighth time Article 4 had ever been invoked, and the first time Russian drones had been shot down over NATO territory.
Russia said the incursions were inadvertent; analysts and a senior Western military official assessed them as intentional, likely probing Polish air defences. Donald Trump speculated that Russia's drones might have wandered into Poland by mistake. A few days later a Russian drone entered Romania's airspace and was shadowed by Romanian fighter jets until crossing into Ukraine. Mark Rutte demanded Russia "stop violating allied airspace" and warned that "we will defend every inch of NATO territory." Donald Trump posted "What's with Russia violating Poland's airspace with drones? Here we go!" on Truth Social, but no further action followed. Article 5, the collective-defence clause, has been invoked only once in NATO's history, on September 11th 2001.
Since 2023 there have been at least 11 suspected acts of sabotage to Baltic Sea infrastructure, many linked to Russia's shadow fleet. The worst were ruptures of the Balticconnector gas pipeline (linking Finland and Estonia) and of a power cable between the two countries, probably caused by ships dragging their anchors along the sea floor; both took months to repair.
In 2025 NATO launched Baltic Sentry, a new maritime mission to protect undersea cables and pipelines in the Baltic Sea from Russia's shadow fleet. Two naval groups, each with seven or eight ships from different countries, take turns tracking vessels of interest in co-ordination with intelligence centres at NATO's maritime headquarters near London. The mission employs undersea drones, sonar systems and divers to monitor infrastructure. Britain challenges more than 40 suspicious ships a month. There have been no incidents of damage to undersea infrastructure since Baltic Sentry began, suggesting the new tactics are working.
NATO deploys "forward" battlegroups in eight countries, from Estonia down to Bulgaria, involving troops from 28 separate countries. American troops are present in at least three of them. NATO increasingly "shadows" Russian exercises, monitoring and matching surges of Russian troops near the border.
The accession of Sweden and Finland has drastically worsened Russia's strategic position in NATO's north. Danish intelligence assesses it would take five years for Russia to be ready for a large war not involving America, but only two years to prepare for a "regional war" against several Baltic countries, and six months for a "local war" against a single neighbour. Lithuania's defence intelligence agency considers a large-scale conventional attack unlikely in the medium term but warns that Russia may develop capabilities sufficient for a limited action against one or several NATO countries. Sweden's spy agency considers a limited armed attack against a Baltic state or NATO ships "entirely possible".
New figures from SIPRI, a Swedish think-tank, show that NATO members excluding America increased spending by $68bn, or 19%, in 2022-23.
European forces are well armed on paper but would struggle to target long-range weapons, organise complex air operations, command large formations and defeat Russian air defences without American involvement. Poland, for instance, has many long-range rocket launchers but lacks the means to find targets for them far behind the front lines. America operates roughly 250 dedicated military satellites; Europe has around 50, many designed for narrow national missions rather than a shared purpose.
The summit was a short, tightly choreographed affair, minimising opportunities for Trump to cause a ruckus, as he did in 2018 when he came close to announcing that America would leave the alliance. The communiqué—the shortest in recent times—set 2035 as the deadline for the new spending target, after fiscally pressured states overruled those pushing for 2032. Allies must submit annual plans showing a "credible, incremental path" and face a bigger review in 2029. Instead of committing "all allies" to the target, the communiqué omitted the word "all", leaving Spain a tacit exemption; Marco Rubio, America's secretary of state, called this "a big problem". Robert Fico, Slovakia's prime minister, said his country had "other priorities in the coming years than armament".
Russia is rebuilding its forces faster than previously thought. NATO had assumed it would take Russia seven years after any ceasefire in Ukraine to reconstitute forces for a confrontation; the general assessment is now five years. Dovile Sakaliene, Lithuania's defence minister, warned: "2035 is after the [next] war."
Volodymyr Zelensky attended a dinner on June 24th but was pointedly excluded from the main meetings the next day. The communiqué watered down its language on Russia: it appeared once, compared with 43 times at the Washington summit the year before. Trump questioned his commitment to Article Five—"It depends on your definition," he said—but did not disrupt the private meeting, declaring NATO "not a rip-off".
Mark Rutte, NATO's secretary-general, employed a strategy of elaborate flattery towards Trump, texting him that Europe was "going to pay in a BIG way" and calling him "Daddy"—earning the sobriquet of the continent's "Trump-whisperer". Rutte said the new spending plans required a 400% increase in air and missile-defence systems, provoking an "audible gasp in the room" of military planners. He warned against a "hockey stick" approach in which allies spend all the money in the last year or two. Non-American members of NATO doubled their spending on equipment between 2018 and 2024, a period in which America's grew by just 5%, according to Janes, a military data firm. America's share of NATO's total investment spending has fallen from 83% in 2010 to 65% in 2025. European allies are poised to outspend America on defence in 2025.
General Chris Cavoli departed as Supreme Allied Commander Europe (SACEUR) in mid-2025 after three years in the job. His replacement is Alexus Grynkewich, an air force general. General Chris Donahue of Allied Land Command developed an "Eastern Flank Deterrence Line" concept in which NATO ground forces, drawing on lessons from Ukraine, use "new forms of mass"—drones and cheaper cruise missiles—to defeat a larger Russian force. The concept was refined in simulations and faces final validation in a major exercise, Steadfast Defender, in May 2026.
NATO's expansive definition of military expenditure includes pensions, barrack upkeep, humanitarian missions and border-agency support—much of which does not directly boost deterrence. Spending is split into four categories: personnel, equipment, infrastructure, and "other" (mainly operations and maintenance). Italy and Belgium spend nearly 20% of their military budgets on retirement cheques. Personnel costs as a share of total expenditure have fallen from about 60% in 2014 to 33%, largely owing to a European hardware splurge since the 2022 invasion of Ukraine. France wants increased military spending to benefit European industry; central and eastern European members continue to buy heavily from America.
NATO was founded in 1949 and has 32 members. All but ten meet the current 2% spending target, compared with 25 delinquents a decade ago. At the June 2025 summit the alliance raised its equipment-spending target from 20% to one-third of military budgets. Virtually all members now meet the 20% equipment-spending threshold. NATO asks members to focus procurement primarily on deterring Russia rather than building forces for a range of scenarios. Greece spends among the highest shares of its military budget on equipment, but much of it is focused on countering Turkey, not Russia.
Admiral Giuseppe Cavo Dragone, head of NATO's Military Committee, has called for a "multi-speed approach" in which bigger armed forces project power while smaller states focus on logistics or cyber-security. Luxembourg, with just 900 soldiers, provides space-based satellite communications and contributes to NATO's spyplane programme. Iceland, which has no armed forces, operates an air-defence and surveillance system. Spain leads a brigade-sized multinational force in Slovakia; Italy oversees one in Bulgaria. Portuguese fighter aircraft patrol the skies over the Baltics.
A 2024 Gallup survey asked citizens in 45 countries how willing they would be to take up arms in case of war. Four of the five least enthusiastic countries globally were in Europe, including Spain, Germany and Italy, where just 14% of respondents said they were willing to fight. Even in Poland, which shares borders with Ukraine and Russia's Kaliningrad exclave, fewer than half said they would fight. In a separate poll taken before the invasion, 23% of Lithuanian men said they would rather flee abroad than fend off an attack. J.D. Vance, America's vice-president, in March 2025 dismissed the possibility of "some random country that hasn't fought a war in 30 or 40 years" credibly deterring Russia.
Some countries, including Denmark and Greece, never fully abolished conscription. Others, such as Poland, are now talking of bringing some form of it back. Despite a halving in troop numbers since 1990 in many countries, non-American NATO members still have more soldiers than America, and roughly as many as a share of their overall population.
Manufacturing made up around €2.5trn of value added in the EU in 2024, about 16% of the total, down from 20% in 1995. Modelling by EY estimates the European parts of NATO will need to spend around €137bn annually on equipment, some €65bn more than the current figure. The resulting increase in spending on Europe's own defence sector and supply chain would be €35.7bn—roughly 1.5% of the EU's manufacturing total—creating perhaps 500,000 jobs, of which 150,000 would be in the defence sector itself. Total employment in Europe's biggest defence firms rose from around 250,000 in 2021 to 280,000 in 2024, before most new orders arrived.
Governments have agreed on €150bn in EU loans to groups of two or more countries for common defence procurement; the European Defence Fund aims to foster cross-border collaboration in research and development. European arms-makers such as KNDS and Thales are building ammunition, spare parts and new weapons in Ukraine, which was home to large parts of the Soviet Union's advanced weapons production. Germany has announced it will pay for long-range missile production in Ukraine, following Denmark's example.
Between February 2022 and September 2024 American weapons accounted for a third of European procurement spending, according to the International Institute for Strategic Studies. Investment in military research and development in Europe was a meagre €13bn in 2024, well behind the $148bn spent in America, according to the Kiel Institute. European local suppliers are close to meeting demand for artillery shells and howitzers, and have expanded production of tanks and fighting vehicles, but the development of advanced kit such as rocket artillery, long-range missiles and air defences is "limited at best and absent at worst". The European Commission's "Readiness 2030" white paper, published in March 2025, concluded that the continent's companies are "not able to produce defence systems and equipment in the quantities and speed that member states need".
Mark Rutte says Europe is on track to produce 2m rounds of artillery ammunition annually by the end of 2025. Raytheon, which makes Patriot missiles, collaborates with MBDA Deutschland to produce the interceptors in Germany—feeding Ukraine from that production line could serve as a compromise between buying American and building European. Some capabilities only America can provide: the French-Italian SAMP/T air-defence system is not as good at shooting down ballistic missiles as America's Patriot, and Europe has yet to field its own equivalent of the HIMARS rocket launcher or the Tomahawk cruise missile.
Kearney, a consultancy, warns of a severe shortage of workers with the right skills for modern defence manufacturing. Job losses elsewhere—especially in Germany's car industry—could help fill the gap, though workers would need reskilling.
In May 2025 the European Commission launched SAFE (Security Action for Europe), a €150bn ($174bn) fund offering EU members low-interest loans for defence investments, aimed at tackling Europe's most glaring capability gaps and boosting industrial capacity through common procurement. When the deadline passed on November 30th 2025, 19 countries had applied and the fund was fully subscribed. Poland alone requested €43.7bn.
The second pillar of the EU's "Readiness 2030" plan is the National Escape Clause (NEC), which lets countries increase defence spending by up to 1.5% of GDP over four years without falling foul of EU deficit rules. By December 2025 sixteen countries had signed up. The NEC could unlock a further €650bn.
The International Institute for Strategic Studies (IISS), a British think-tank, reckons Russia could pose a direct threat to Europe as soon as 2027. In purchasing-parity terms Russia will spend as much on defence as all of European NATO combined. The IISS puts the cost of replacing American non-nuclear capabilities assigned to NATO at about $1trn.
Camille Grand, a former NATO assistant secretary-general, says that European defence spending is already 50% higher in nominal terms than in 2022 and expects it to rise to between €500bn and €700bn a year over the next five years, about 30% of it for procurement.
The seven-country European Long-Range Strike Approach (ELSA), a project to develop a ground-based cruise missile, is necessary for scale and commonality—but nearly 18 months after ELSA was formed there is no agreement on what MBDA, Europe's missile champion, should build.
A long-running recruitment crisis has left many Western forces unable to fill even their smaller post-cold-war armies. The American army missed its recruitment targets in 2022 and 2023 by 25%, equating to about 15,000 active-duty soldiers per year; the Pentagon called 2023 the "toughest year" since the inception of an all-volunteer force in 1973. Canada, Australia, Japan and New Zealand have all struggled to recruit enough regulars.
Only 23% of Americans aged 17–24 met the requirements to join up based on weight, medical conditions and previous drug usage, according to a Pentagon study. In 2022 the US Army instituted a Future Soldier Preparatory Course, offering 30–90 days of physical training and schooling to help willing recruits meet the minimum standard; more than 51,000 trainees have joined the army through it. Latvia, Lithuania and Sweden have reintroduced mandatory national service. European countries that allow lottery-based conscription, such as Denmark, Latvia and Lithuania, have seen their armies filled mostly with volunteers.
By 2025 the recruitment picture had improved. America's army met its target four months ahead of schedule. Canada and Australia met recruitment targets for the first time in over a decade. But retention remains a problem: people are leaving the armed forces almost as fast as they join.
America's month-long bombing of Iran (in partnership with Israel) in March–April 2026 produced the worst row in the alliance's history, according to Ivo Daalder, a former American ambassador to NATO. Donald Trump grew furious at European allies' refusal to send ships to reopen the Strait of Hormuz—which carries about a fifth of global seaborne oil, and similar shares of liquefied natural gas and fertiliser—and some allies' reluctance to facilitate American operations. After a ceasefire on April 7th, Trump posted "NATO WASN'T THERE WHEN WE NEEDED THEM."
Spain was the most confrontational: it closed its bases and airspace to American forces. Italy stopped some American planes from using a base in Sicily. France sent fighter jets to help the United Arab Emirates and an aircraft-carrier to defend Cyprus. Britain initially refused its bases, later permitting their use only to protect neighbouring countries from Iran's retaliation.
Marco Rubio, once a staunch defender of the alliance—he co-sponsored a 2023 Senate law to block unilateral withdrawal without a two-thirds vote—called NATO "a one-way street" and said America would "re-examine that relationship" after the Iran conflict. Kurt Volker, another former American ambassador to NATO, argued that Congress would block any formal departure, but noted that Trump could cripple the alliance without leaving by withdrawing American forces from Europe or recalling its military commander. The Wall Street Journal reported that administration officials were debating a plan to move troops from unhelpful countries to more co-operative ones.
Keir Starmer travelled to Saudi Arabia and other Gulf states to discuss reopening the strait. Emmanuel Macron rejected reopening it by force, insisting on a ceasefire first. France pushed to lead any naval escort mission and exclude America; Britain argued America should spearhead it.
Trump said the rift was caused not by Iran but by European resistance to his desire to seize Greenland. The annual summit is scheduled for Ankara in July 2026.
Several European countries are quietly making plans to fight not just without America's help but without NATO's command-and-control infrastructure, in case America "malfunctions". Mark Rutte, NATO's secretary-general, has banned discussion of a Plan B at NATO headquarters, fearing it would accelerate America's departure. Most coalitions look like a primary-school music practice—everyone bangs roughly in time and leaves—whereas NATO was built as a symphony orchestra led by the Supreme Allied Commander Europe (SACEUR), an American general who also commands American forces in Europe. SACEUR has secure communications links to a network of permanent subordinate headquarters with thousands of personnel.
The Joint Expeditionary Force (JEF) is the most established alternative. Established by Britain and six other NATO members in 2014, the JEF expanded when Sweden and Finland joined the coalition in 2017, several years before they applied for NATO membership. Headquartered near London, it has its own secure communications networks that do not rely on NATO. Unlike NATO's Article 5, which requires unanimity, the JEF "can react to situations on a non-consensus basis", said its then commander, British Major-General Jim Morris, in 2023. The JEF has been activated several times for exercises and naval patrols. Its focus is the Nordic and Baltic regions; it lacks France, Germany and Poland. Britain's underfunded forces have left it with few ships, submarines and army units ready to deploy at short notice. About one-third of NATO members would "fight on day one" irrespective of whether Article 5 is triggered, according to Edward Arnold of RUSI.
In May 2026 America scrapped the planned deployment of the "Black Jack" armoured brigade (4,000 troops) from Fort Hood to Poland, and cancelled the deployment to Germany of a cruise-missile unit that was to plug an important gap in Europe's defence. America's huge expenditure of missiles in Iran is delaying shipments to European allies and Ukraine.
Ukraine's NATO ambitions are "dead" for the foreseeable future, say Western officials. As president, Joe Biden was sceptical about the country joining NATO. Its hopes were killed by President Donald Trump's hostility to the idea and to Ukraine itself. That leaves EU accession as the remaining way for Ukraine to anchor itself in Europe and the wider democratic world.
In the case of a major war in the east, NATO wants to muster around 100,000 troops within ten days, a sharp jump from the 40,000 it budgets for at present, and a further 200,000 within 30 days. Without American boots, Europeans will struggle to meet those targets unless they spend considerably more on recruitment.
Any philosophy that can be put "in a nutshell" belongs there.