European leaders used the opening dinner of the G7 summit in Evian-les-Bains to deliver a candid warning to President Donald Trump: a superficial interim deal with Iran risks entrenching, rather than dismantling, Tehran’s nuclear and ballistic missile programmes. The two-hour discussion, held on Monday evening around a table overlooking Lake Geneva, set the tone for a gathering where transatlantic tensions over Iran and Ukraine are being laid bare. Trump arrived buoyed by the preliminary agreement reached with Iran, which he signed virtually on Sunday and hailed as a “great success”, with a formal signing targeted for Friday. Yet European officials left the dinner with unanswered questions, particularly about the speed at which the Strait of Hormuz could be reopened to commercial shipping — a chokepoint whose closure has rattled global energy markets.

Viewed from Paris, Berlin and London, the concern is that a hastily arranged interim accord could legitimise and lock in Iran’s nuclear infrastructure and its expanding ballistic missile arsenal, rather than rolling them back. President Emmanuel Macron stressed that the priority must be a “solid, serious and finalised” agreement, echoing a broader European insistence that any deal must include robust verification mechanisms and address missile proliferation. The European Union’s representatives at the summit share this unease, fearing that a temporary truce might simply buy Tehran time while leaving the core strategic threat intact. These anxieties are compounded by the fact that the text of the preliminary deal has not been published, leaving allies to parse conflicting signals from Washington.

A central point of friction is the timeline for clearing naval mines and restoring freedom of navigation through the Strait of Hormuz. American officials, ahead of the summit, signalled they expected European nations to contribute to post-conflict minesweeping operations. However, European diplomats noted that US responses on how quickly the strait could be made safe for commercial traffic varied markedly over the past day, fuelling doubts about operational planning. The strait’s reopening is not merely a technical matter; it is a barometer of whether the wider conflict is genuinely de-escalating or merely pausing under terms favourable to Iran.

The Iran file is not the only source of friction. European leaders are also pressing Trump to reconsider his approach to Ukraine, though the details of that parallel conversation remain less public. The dual agenda underscores a broader dynamic at this G7: European allies are seeking to tether an unpredictable American president to multilateral, verifiable frameworks, wary that bilateral dealmaking could undermine long-term stability in both the Middle East and Eastern Europe.

As the summit continues, the formal signing of the Iran deal on Friday will be scrutinised for evidence that European concerns have been heeded. The gap between Trump’s characterisation of the accord as a breakthrough and Europe’s insistence on a comprehensive, enforceable agreement remains wide. Whether the final text bridges that gap — and whether Washington can offer credible assurances on the Strait of Hormuz — will determine if this summit marks a genuine transatlantic convergence or merely papers over strategic divergence.