Trump’s War on Iran: A Strategic Test Europe Was Not Ready For

The US-Israeli military campaign against Iran has rapidly become more than a regional conflict. For Europe, it is a geopolitical stress test — one that has exposed deep divisions over international law, transatlantic loyalty, and the limits of the EU’s strategic autonomy.

When US and Israeli forces launched large-scale strikes on Iran under what the Pentagon has called “Operation Epic Fury”, European governments were caught off guard. According to the Council on Foreign Relations, Washington launched the operation with little to no prior consultation with its European allies — despite expecting to use their bases and receive their broad political support. It was not the first time. As CFR senior fellow Matthias Matthijs noted, Europe had already been left in the dark over the US capture of Venezuelan leader Nicolás Maduro. The Iran strikes followed the same pattern.

The result has been what Matthijs describes as “a strikingly disjointed European response” — a patchwork of cautious statements, legal objections, domestic political calculations, and quiet hedging that has highlighted how difficult it remains for the EU to act as a unified geopolitical force when it matters most.

The EU’s opening response

The first institutional reaction from Brussels was measured. In a joint statement, as reported by Euronews, European Commission president Ursula von der Leyen and European Council president António Costa described the situation as “greatly concerning” and called on all parties to “exercise maximum restraint, to protect civilians, and to fully respect international law”. Von der Leyen announced she was convening a special security college and said the EU was exploring “diplomatic paths” with Arab nations.

The EU’s chief diplomat, Kaja Kallas, struck a somewhat different tone — acknowledging that Iran’s regime “has killed thousands” and that its ballistic missile and nuclear programmes “pose a serious threat to global security”, while insisting that the protection of civilians and international humanitarian law remained a priority. The EU’s Aspides naval force, she added, remained “on high alert” in the Red Sea.

According to the Guardian, French president Emmanuel Macron was more direct, calling the strikes an “outbreak of war” that “carries serious consequences for international peace and security” and calling for an urgent UN Security Council meeting. European Parliament president Roberta Metsola warned against “a spiral of escalation that could threaten the Middle East, Europe and beyond”.

The fractured European response

Behind the shared diplomatic language, the crisis quickly revealed how differently European governments read the same situation.

France took the most legally assertive position among the major powers. Macron warned that military action conducted outside international law risks undermining global stability and pushed for emergency UN Security Council discussions. At the same time, Paris avoided direct confrontation with Washington and strongly condemned Iranian retaliation. Macron ordered France’s Charles de Gaulle aircraft carrier and other military assets to the region to protect French interests, including its Camp de la Paix base in Abu Dhabi — a response that tried, as the CFR noted, to “defend the principle of international legality while maintaining strategic alignment with the United States”.

Germany took the most sympathetic position toward US and Israeli goals. Chancellor Friedrich Merz described Iran as a major security threat and argued that decades of diplomacy had failed. Before flying to Washington, he said: “Now is not the moment to lecture our partners and allies.” At the White House, Merz said the two sides were “on the same page” and focused the conversation on preparing for “what will come the day after” — a framing that sidestepped the unresolved question of the strikes’ legality.

The United Kingdom found itself in the most uncomfortable position of all. Prime Minister Keir Starmer initially did not allow US forces to use Diego Garcia or UK airbases, citing doubts about the legality of the strikes. That position shifted on Sunday after Iran launched retaliatory missile and drone attacks across the region — including one that hit a UK airbase in Cyprus and struck airports and hotels where British citizens were staying.

In a video message, Starmer explained that the US had requested permission to use British bases “for that specific and limited defensive purpose” — targeting Iranian missiles in storage depots or launchers. “Iran is striking British interests nonetheless and putting British people at huge risk,” he said, framing the decision as one of collective self-defence in accordance with international law. British fighter jets were already intercepting Iranian strikes. Trump, nonetheless, criticised London for taking “far too long”.

Spain draws the clearest line

The sharpest European rejection came from Madrid. According to the Guardian, Spain’s Prime Minister Pedro Sánchez explicitly condemned the US and Israeli action as an “unjustified and dangerous military intervention” and refused to allow US forces to use the jointly operated bases at Rota and Morón. Foreign minister José Manuel Albares was unambiguous: “The bases are not being used — nor will they be used — for anything that is not in the agreement or for anything that isn’t covered by the UN charter.”

Trump responded by threatening to cut trade ties with Spain. Sánchez did not back down.

Flight tracking data from Flightradar24 showed that 15 US aircraft had departed Rota and Morón since the strikes began, with at least seven landing at Ramstein Air Base in Germany. US defence officials declined to comment on the departures.

The Atlantic Council’s Andrew Bernard attributed Sánchez’s position partly to domestic politics — his left-wing coalition government faces regional elections this year and national elections in 2027, and confronting Washington and Israel “resonates with certain sectors of the electorate”. Italy’s government also raised legal concerns, with defence minister Guido Crosetto describing the strikes as inconsistent with international law, though Rome remained politically closer to Washington than Madrid.

Poland, by contrast, offered clear political backing for the operation, with President Karol Nawrocki framing Iran as a broader threat to international stability. Similar support came from the Baltic states, the Czech Republic, and Romania — reflecting the eastern flank’s deeper alignment with Washington on security matters.

The transatlantic contradiction

The Washington Post captured the central tension in its headline: Trump’s team had spent the better part of a year publicly criticising European governments, and now Washington was asking for their support in a war it had launched without consulting them.

That contradiction has not been lost on European policymakers. According to the CFR analysis, in 2025 European governments had largely tried to avoid confrontation with Washington even as US policy toward its allies became increasingly hostile — a strategy Matthijs and co-author Nathalie Tocci described in Foreign Affairs as “little more than a holding operation”. By early 2026, Europe had begun to act more assertively: agreeing on a €90 billion loan package for Ukraine, pushing back on Trump’s threats over Greenland, and responding with coordinated retaliatory measures when Washington threatened new tariffs.

The Iran conflict now poses a fresh test of that trajectory. As the CFR piece argues, Europe has limited strategic weight in the conflict itself and faces an increasingly strained relationship with its most important ally. For many governments, the priority remains Ukraine — and a prolonged US military engagement in the Middle East risks distracting Washington from the European theatre at precisely the wrong moment.

A crisis with European consequences

The war’s economic fallout is already reaching Europe. The Strait of Hormuz — through which roughly 20 per cent of the global oil supply passes — has seen major disruptions following Iranian attacks on regional shipping. Oil prices rose more than 5 per cent on the first day of the conflict, according to the Atlantic Council, and could spike further if the strait closes entirely.

Higher energy prices benefit Russia’s export revenues and strengthen Moscow’s capacity to finance its war against Ukraine — a point noted by retired Ukrainian Major General Volodymyr Havrylov, a nonresident senior fellow at the Atlantic Council’s Eurasia Center. While many Ukrainians felt a degree of schadenfreude at seeing Iran — a key supplier of Shahed drones used against Ukrainian civilians — come under attack, Havrylov cautioned that the war also places new pressure on air defence interceptors that Ukraine urgently needs and gives Russian propagandists fresh material to justify Moscow’s own military campaign.

What the crisis reveals

The Atlantic Council’s Roderick Kefferpütz identified three competing logics pulling European governments in different directions: some prioritise international law and the rules-based order; others prioritise transatlantic cohesion and avoiding confrontation with Washington; and others quietly hope the strikes weaken Iran’s regime and reduce its nuclear and proxy threats. “Europe is trying hard to reconcile these three concerns,” he wrote, “but finding common ground is difficult.”

That difficulty is structural. The EU still lacks rapid decision-making mechanisms capable of producing a unified foreign policy response to major crises. It remains militarily dependent on the United States. And internal divisions between member states make it hard to balance alliance commitments with national interests and legal principles.

The Iran war has not created these weaknesses – it has exposed them. How European leaders navigate the weeks ahead will say a great deal about whether the continent’s stated ambition of strategic autonomy is a direction of travel or simply a phrase.