Trump's security strategy downgrades Europe as US forces shift east

The United States has already pulled tactical aviation, naval and air defence assets from Europe and sent them to the Persian Gulf and Indian Ocean for the war with Iran. That fact alone tells European governments more about the Trump administration's commitment to their defence than any communiqué from Washington. The National Security Strategy, published earlier this year, makes the order of priorities explicit: defend the American homeland first, deter China in the Indo-Pacific second, increase burden-sharing with allies third. Europe does not appear on the list as a priority in its own right.

What the National Security Strategy actually says

The document's top three priorities are quoted directly. The first is "Defend the U.S. Homeland". The second is "Deter China in the Indo-Pacific Through Strength, Not Confrontation", which includes a "Sea Denial" strategy to prevent Chinese access to the First Island Chain. The third is "Increase Burden-Sharing with U.S. Allies and Partners." The first two are described as interchangeable. Europe appears only in the third priority, and then as a place where others should shoulder more cost, not as a region the US has a primary interest in defending.

The strategic shift towards the Pacific began under Barack Obama in 2011, with his "pivot" to Asia, announced with so little consultation that it startled allies in both Europe and Asia. Trump has accelerated the trend, adding a harder edge: burden-sharing is now framed not as a shared goal but as a transactional demand, accompanied by threats of consequences if European governments do not comply.

Forces already leaving the continent

The redeployment of US assets to the Gulf is not a projection. It has happened. Air Force General Alexus Grynkewich, currently serving as NATO's Supreme Allied Commander Europe, has complained that his naval forces are insufficient to defend Israel from missile attack. If the commander of all allied forces in Europe says he lacks the ships to carry out a mission outside Europe, the shortfall in European-based US forces is no longer hypothetical.

Further withdrawals remain possible. Trump has feuded publicly with Spain's Prime Minister and could remove US destroyers from their base at Rota. Forces stationed in Romania, Poland and Turkey could be reduced. The administration's national security focus on preventing a Chinese invasion of Taiwan and on homeland defence leaves European contingencies as a lower-tier concern, regardless of how the war in Ukraine is resolved.

The Article 5 wording that matters

NATO's founding commitment, Article 5 of the Washington Treaty, states that an armed attack against one ally "shall be considered an attack against them all." The phrasing has always mattered. "Shall be" is not "will be." It is a commitment to treat an attack as shared, not an absolute guarantee of a military response. For decades, that distinction was academic: the political assumption was that the United States would respond with overwhelming force. Under Trump, the distinction is no longer academic.

As the analysts David Richards and Harlan Ullman argue in a forthcoming book, "Who Thinks Best Wins", one should not dismiss a narrower reading of Article 5 while Trump remains in power. The president has repeatedly threatened European allies with consequences if they do not spend more on defence, implying that American protection is conditional. If the US administration treats the alliance's central guarantee as negotiable, the entire structure of European deterrence shifts.

Golden Dome and the nuclear balance

The first priority in the National Security Strategy, homeland defence, includes a plan for what the administration calls "Golden Dome": a missile shield covering the entire United States, including Alaska, Hawaii and overseas territories. The concept echoes Ronald Reagan's Strategic Defense Initiative of the mid-1980s, widely known as Star Wars, which failed because it could not reliably defend against air-breathing missiles, ballistic warheads and submarine-launched threats simultaneously. Modern technology has advanced since Reagan's era, but so have costs.

The consequences for Europe are twofold. First, the money for Golden Dome must come from somewhere, and conventional forces are the most likely source. A missile shield on that scale would absorb billions of dollars that would otherwise fund the army, navy and air force units currently stationed in or available for Europe. Second, and more troubling, if Golden Dome works, it would alter the nuclear balance. Russia would inevitably try to replicate the technology. If Moscow succeeded, the deterrent value of French and British nuclear forces, and of the American theatre nuclear weapons scattered across Europe, would be diminished. A shield that protects the United States but cannot protect Europe would leave the continent more exposed, not less.

The SACEUR tradition under pressure

Since General Dwight D. Eisenhower took the post in 1951, the Supreme Allied Commander Europe has always been an American. The tradition has served two purposes: it tied the United States to the defence of Europe, and it assured European governments that American strategic and tactical nuclear arsenals were linked to the continent's security. The SACEUR was both a military commander and a political symbol.

That symbol is now under strain. The Trump administration has downgraded the European command structure in line with its intention to reduce forces. If the SACEUR post were eventually filled by a non-American, it would signal a fundamental change in the alliance's character. Richards and Ullman argue that the single most important step NATO can take is to insist that future SACEURs remain American, because the position is the bond that keeps the alliance whole. Yet insisting on an American SACEUR while American forces shrink creates its own tension: a commander with fewer troops and less political backing from Washington.

Spending more does not mean defending better

Trump's insistence that European allies spend more on defence is not new. Every American administration since 1949 has pressed Europe to carry a larger share of the burden. What is different now is the coercive tone and the implied threat that spending too little could cost an ally its protection under Article 5.

The trouble is that higher national defence budgets do not automatically produce a stronger alliance. If Germany, Spain and Italy each increase spending by half a percentage point of GDP, the result is more money but not necessarily more capability. Without a plan to coordinate that spending, to avoid duplication and to fill the specific gaps that US redeployments have left, the additional funds could end up reinforcing national forces that do not work together. Richards and Ullman draw a parallel with the "deep strike" doctrine of the early 1980s, which used Western technological superiority to counter Soviet numerical advantages. That doctrine worked because it was a coordinated alliance strategy, not a collection of national shopping lists.

What a porcupine defence would look like

Richards and Ullman propose what they call a "porcupine defence" for NATO: an alliance-wide posture designed to make any initial Russian attack so obviously costly that Moscow would not attempt it. The concept would require coordinated deployment across the Baltic states, central Europe, and the northern and Black Sea flanks. Crucially, they argue it could be achieved without pushing defence spending to 3.5 per cent of GDP, the figure some advocates have demanded.

The idea draws on the lesson of Ukraine, where a smaller force armed with Western technology has fought a larger military to a standstill. If NATO can organise its existing and planned forces to achieve the same effect at scale, the porcupine approach could provide deterrence without requiring every member to match an arbitrary spending target. The challenge is political, not just military: it requires allies to agree on where the porcupine's quills go, and who pays for them.

Robert Ondrejcsák, executive director of the European Leadership Network, argues that Europe's priority should be strengthening alliance capabilities rather than creating parallel structures. Tarja Cronberg, writing for the same network, says the upcoming NATO summit in Ankara will test whether allies can move beyond technical arguments about spending percentages and articulate a collective vision for Europe's future security order. Alexander Graef, the network's programme lead, observes that NATO's adaptation process and unilateral US decisions have already created the foundations for a larger European role in transatlantic security. Whether Europeans can sustain that role politically remains uncertain.

The Ankara summit, expected to address these tensions directly, will be the first real test of whether the alliance can adapt its command structure and force posture to a reality where the United States is a less reliable partner. The question is not whether Europe will spend more. It almost certainly will. The question is whether that spending will be coordinated enough to produce a genuine deterrent, or whether it will produce a set of national armies that look stronger on paper but remain fragmented in practice.