Warren Stephens, Donald Trump’s ambassador to the United Kingdom, laid a white floral wreath at the September 11th Memorial Garden in Grosvenor Square on Friday, honouring the 67 British citizens killed in the attacks a quarter-century ago. The gesture was modest. The weight behind it was not.
Speaking at a dedication ceremony for a new memorial stone at the US embassy in London the previous day, Stephens offered a pointed reminder of what the alliance has historically meant. Britain rallied, he said, in “one of America’s darkest hours”. More than 1,000 letters and flowers sent by members of the public from across the United Kingdom remain preserved in the embassy’s archives — an unremarkable detail, perhaps, until one considers what it represents: a spontaneous, nationwide expression of solidarity that no diplomatic communiqué could replicate.
The ambassador was direct about the broader relationship. “Despite our disagreements and debates,” he said, the transatlantic partnership “has kept us safe for centuries.” That framing matters. It acknowledges friction without surrendering to it — a position that has become harder to maintain as the current administration in Washington has strained ties with traditional allies on multiple fronts, most visibly over Iran.
What did 9/11 actually demand of Britain?
The attacks on 11 September 2001 killed 2,977 people when al-Qaeda hijackers struck the twin towers of the World Trade Centre and the Pentagon. A fourth aircraft, United Airlines Flight 93, came down in rural Pennsylvania after passengers and crew overpowered the hijackers, almost certainly preventing an assault on the US Capitol. It remains the deadliest terrorist attack in recorded history, drawing victims from more than 90 nations.
The institutional response was historic. The United States became the first — and to date the only — nation to invoke Article 5 of the NATO treaty, the collective defence clause obliging member states to treat an attack on one as an attack on all. Britain answered that call without hesitation. What followed was two decades of large-scale military commitment in Afghanistan and Iraq, costing hundreds of British lives, leaving thousands more injured, and generating consequences that continue to reverberate across the Middle East and Central Asia.
That history provides essential context for Friday’s commemorations. Prime Minister Andy Burnham, attending ceremonies in London, wrote in a note placed on a memorial wreath: “In memory of those we lost and in defence of the values we share. Whilst we stand together for freedom and democracy, terror will never define us.” He also drew a direct line between 9/11 and the Manchester Arena bombing of 2017, noting that American survivors of the September 11 attacks had sent messages of support to his city in the aftermath of that atrocity.
Former Prime Minister Sir Tony Blair, who led Britain through the immediate aftermath of the attacks and the decisions that followed, described the anniversary as an occasion to “commemorate the unshakeable and essential bond” between the two countries. Blair’s words carry particular weight: few figures understand more concretely what that bond has cost, and what it has preserved.
The day’s ceremonial programme concluded with the Duke and Duchess of Gloucester taking the Royal Salute on the Buckingham Palace forecourt, accompanied by Ambassador Stephens — a formal expression of continuity in a relationship that has, over 25 years, been tested by war, political turbulence, and now renewed uncertainty about American strategic commitments to its allies.
The question the anniversary quietly poses is whether the institutional architecture built on that post-9/11 solidarity — NATO commitments, intelligence-sharing, military interoperability — retains the political will to sustain it. Stephens’ remarks suggest he, at least, believes it does. The record of the past 25 years gives reasonable grounds for that confidence. The record of the past several months gives reasonable grounds for caution.