US-Iran War's Return May Leave Europe Short of Arms When It Needs Them Most

Fresh U.S.-Iran clashes paired with President Donald Trump’s threats to scrap a ceasefire deal have once again pushed the Persian Gulf to the brink of a full-scale war.

But the impact is far from limited to the Middle East. As Trump returns from a NATO summit in Turkey, European allies already reeling from the U.S. leader’s criticism are bracing for further shortfalls in procuring U.S. arms at a volatile moment for their region as well, with the Russia-Ukraine war also escalating on the alliance’s borders.

European leaders have long called for greater security autonomy, ramping up defense spending to expand the military-industrial base in recent years. But analysts have warned these efforts have fallen short.

And as European nations now scramble to accelerate the massive rearmament campaign in response to growing global unrest, time is not on their side.

“Europeans have realized that they can no longer rely on the U.S. as they did in the past and are investing at both national and EU levels to develop a credible European defense,” Pierre Haroche, a European security expert and associate professor at the Catholic University of Lille’s European School of Political and Social Sciences, told Newsweek.

“The main challenge lies in the period between now and the time when Europe is ready,” Haroche said. “The risk is that Russia could take advantage of this window of opportunity, during which the U.S. has already reduced its commitment and Europeans are not ready yet.”

Lacking Coordination

The primary obstacle identified by Haroche is a lack of coordination.

As the European Union seeks to develop its own military build-up in parallel with primarily U.S.-led NATO structures, each member state has its own interests. Disparities and questionable practices in spending have been a key source of criticism from Trump, who reiterated his grievances at the latest NATO gathering.

Even at the level of EU leadership, there have been inconsistencies. The European Commission is spending hundreds of billions on programs such as the Security Action for Europe (SAFE) and the European Defense Fund, yet the EU just last year signed a major trade deal committing the bloc to purchasing substantial quantities of U.S. military equipment.

The U.S.-EU trade deal was hailed by EU officials as a step in easing tensions with the Trump administration, but the move also risked deepening dependence on the U.S. as new questions surface over Washington’s long-term commitments. And as the EU moved to shift focus on domestic investments, NATO Secretary-General Mark Rutte has hit back with an appeal for even greater synergy between European and U.S. military capabilities.

The paradox mirrors some apparent contradictions in the White House’s own approach. Trump has simultaneously exerted pressure on allies to purchase more U.S. arms and demanded they contribute more for their own defense, putting Europe in a difficult position.

The U.S.-Israeli war launched against Iran in February has only exacerbated European concerns, with costly stockpiles depleting and transatlantic shipments waning.

The Russia-Ukraine war, Europe’s deadliest conflict since World War II, is also undergoing a period of heightened conflict marked by both sides stepping up destructive long-range strikes. Should the battle cross the border into NATO territory, as it has threatened to do on several occasions, European nations may find themselves woefully unprepared.

“A war against Russia would require a massive production of drones and missiles every year, following the Ukrainian model,” Haroche said. “This calls for a coherent defense industrial strategy on a continental scale. The European Commission is pushing in this direction, but member states remain keen to defend their prerogatives.”

“The risk is that, in the event of a high-intensity war on a European scale, European industry would be unable to overproduce Russia, due to its fragmentation,” he added.

The ‘Deterrence Gap’

It’s not just the production matters, but also perception.

Claudia Major, senior vice president of the German Marshall Fund of the United States who previously served at the German Foreign Office’s NATO Department, warned of “a deterrence gap-a situation in which adversaries perceive a mismatch between Europe's interests and its ability or willingness to defend them.”

“Such a deterrence gap can emerge gradually, through ambiguity, delayed reactions, and mixed signals, especially in moments of crisis when credibility matters,” Major told Newsweek. “Deterrence rests not only on capabilities but also on perceptions.”

“Are NATO allies able to demonstrate that they all stand together in case of a crisis or attack? If Allies come across as a divided lot, whom one can hardly believe would stand up for one another, then NATO's credibility is at stake-and with it, Europe's security,” she said.

Trump has brought these divisions to the forefront. Feeling spurned by European allies over their perceived lack of support in the Iran war, he has repeatedly warned that the U.S. may reciprocate in rejecting their calls for help should the time come.

The feud could serve as a message to Russian President Vladimir Putin, who has long bet on NATO infighting disrupting the alliance’s unity in support of Ukraine and its own defense. Though still mired in Ukraine, Moscow has consistently demonstrated the ability to adapt its arsenal and strategy in ways that could pose a major threat to NATO in its current state.

“If Russia comes to believe that Washington might hesitate to support Europeans, and Europe lacks the cohesion or capabilities to compensate, then Russia might be tempted to test European deterrence and defense,” Major said.

The situation could go grow particularly dire, Major warned, should the U.S. “further reduce its security contributions to NATO, potentially in a disruptive, uncoordinated way, forcing Europeans to step up much quicker than they are able to.”

‘Buy Better, More Quickly, and Differently’

Recognizing this challenge, Guntram Wolff, senior fellow at the Bruegel think tank who has advised the European Commission, told Newsweek that “Europe definitely will need to bolster its domestic defense industrial base as the U.S. will use its production capacities for its war in Iran and elsewhere.”

There are signs of progress, however.

As Wolff pointed out, “European production has already increased substantially and in some weapon systems now outpaces that of the U.S.” He also highlighted that “European orders to defense companies have increased massively,” therefore, “we do not have a spending problem anymore.”

Where Europe’s most serious test lies, he argued, was in establishing high-tech capabilities that could operate independently from the U.S. security umbrella.

“The key challenge for Europe is to increase its digital autonomy,” Wolff said, “especially for scenarios where access to U.S. AI systems or communication systems were to get disrupted.”

Therefore, it’s a problem not solely of quantity but also quality. While Europe invests in expanding production lines across the continent, nations must ensure domestic industries keep up with the rapidly evolving demands of modern warfare involving both conventional and hybrid tactics.

“It’s not just a case of buy more and buy more European, but also buy better, more quickly, and differently,” Douglas Barrie, senior fellow for military aerospace at the International Institute for Strategic Studies based in the United Kingdom, told Newsweek. “As such, the challenge is considerable.”

“The European defense industrial landscape remains fundamentally national rather than continental, and national industrial imperatives can run counter to the efficient definition and procurement of weapons,” Barrie said. “There is a risk to credibility and therefore deterrence if such pledges are not pursued adequately.”

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This story was originally published July 10, 2026 at 3:00 AM.