America remembers: twenty-five years after 9/11

Anyone old enough will remember exactly where they were on September 11 2001. Video footage of two airliners smashing into New York's World Trade Center is seared into the memories of millions around the world.

The attacks that day united a nation in grief, patriotism and defiance and prompted an outpouring of global solidarity. A quarter of a century on, that sense of unity has proven increasingly elusive, as Americans' divisions deepen and their politics grow ever more febrile.

But the shock and sadness of 9/11 linger in the collective memory, and on Friday the country will — for a day at least — try to rekindle the common purpose and sense of a shared experience as it marks the 25th anniversary of the tragedy.

When al-Qaeda terrorists hijacked four passenger planes and crashed them into buildings in New York and Washington and a field in Pennsylvania, killing nearly 3,000 people, the nation came together with a unity and purpose that is "distinctively American", President Donald Trump remarked this week.

"We mourned as one people. We prayed as one nation," he said in a statement. "The terrorists sought to break our spirit — they failed. They sought to divide us — they could not."

Images from that fateful day — the shell-shocked office workers, covered with ash, the enormous dust cloud moving through Lower Manhattan and firefighters clambering through smouldering rubble — have flooded US news sites in the run-up to the commemoration.

Haunting recordings of messages left by passengers aboard the hijacked planes and desperate people trapped in the World Trade Center towers have circulated on social media alongside interviews with relatives of the victims still struggling with their own private grief.

As part of the main ceremony of remembrance in New York City on Friday, family members will gather at Ground Zero to read the names of those killed in the attacks. In Washington, Trump and defence secretary Pete Hegseth will honour the 184 people killed at the Pentagon and aboard Flight 77.

And in Pennsylvania, the bells of remembrance will sound to recall Flight 93, which crashed in a field near the town of Shanksville, killing all 40 passengers and crew after they attempted to overpower the hijackers.

Behind the national mourning, debate is still raging over the political meaning of the 9/11 attack, an inflection point in US history as consequential as the Japanese bombing of Pearl Harbor in 1941.

The assault changed the course of US foreign and domestic policy . And it set off a sequence of historic events that reshaped the Middle East and south Asia.