Twenty years have passed since the 9/11 attacks in the USA / Photo: Collected

America marks the 20th anniversary of 9/11 Saturday with solemn ceremonies given added poignancy by the recent chaotic withdrawal of troops from Afghanistan and return to power of the Taliban.

Heart-wrenching commemorations will unfold at each of the three sites where 19 Al-Qaeda hijackers, mostly from Saudi Arabia, crashed packed airliners, striking the cultural, financial and political hearts of the United States and changing the world forever.

The memorials come with US troops finally gone from Afghanistan, but national discord, and for President Joe Biden, political peril, are overshadowing any sense of closure.

In a video posted on the eve of the anniversary, Biden urged Americans to show unity, our greatest strength.

“To me, that’s the central lesson of September 11th. It’s that at our most vulnerable, in the push and pull of all that makes us human, in the battle for the soul of America, unity is our greatest strength,” Biden said in a six-minute message from the White House.

At New York’s Ground Zero, where two pools of water now stand where the Twin Towers used to, relatives will read out the names of the nearly 3,000 people killed in a four-hour-long service starting at 8:30 am.

Six moments of silence will be observed, corresponding with the times the two World Trade Center towers were struck, and fell, and the moments the Pentagon was attacked and Flight 93 crashed.

In the interim, Al-Qaeda founder Osama bin Laden has been hunted down and killed. A towering new skyscraper has risen over Manhattan, replacing the Twin Towers. And less than two weeks ago, the last US soldiers flew from Kabul airport, ending the so-called forever war.

But the Taliban who once sheltered bin Laden are back ruling Afghanistan, the mighty US military humiliated. In Guantanamo Bay, accused 9/11 mastermind Khalid Sheikh Mohammed and four other men continue to await trial, nine years after charges were filed.

Even the full story of how the attack came to happen remains secret. Only last week did Biden order the release of classified documents from the FBI investigation over the next six months.

ARR