Twenty-five years ago, the heinous terrorist attacks of 11 September 2001 against the United States claimed thousands of lives and represented "an assault on humanity itself", the UN chief said on Thursday.
In a statement marking the anniversary, António Guterres paid tribute to victims, survivors and first responders who rushed to ground zero - the World Trade Center's twin towers in New York - just a few miles south of UN Headquarters.
"As we mark this somber occasion on 11 September, we remember the nearly 3,000 victims - from the United States and more than 90 countries - and stand with their families and loved ones," said the UN chief.
The UN continues to stand in solidarity with the people of New York City, the US, and with all those whose lives were affected by the attacks, he added.
Mr. Guterres noted that 2026 also marks 20 years since Member States adopted the UN Global Counter-Terrorism Strategy - reminding that the fight against terrorism is a shared, unfinished task.
"As we pay tribute to the victims, let us renew our shared commitment to build a future free from terrorism."
Toll on human rights
Indeed, many countries made that commitment, strengthening security measures in the wake of the deadly attacks which upended geopolitics across the world.
But, too many nations adopted unnecessary and disproportionate responses that have seriously undermined rights, civil society, civic space, democracy and the rule of law, according to a group of over 30 UN independent experts, who began their statement released on Thursday by paying tribute to all victims of terrorism.
"'Wars on terror' have stretched foundational rules of international law beyond their breaking point," said the UN Human Rights Council -appointed independent experts, who are not UN staff and receive no salary for their work.
Worldwide monitoring over the past quarter century has exposed the gravest violations of international law in the name of countering terrorism, including wars of aggression, unlawful occupations, "countless" war crimes and crimes against humanity as well as plausible allegations of genocide, they said.
They also highlighted assassinations dressed up as "targeted killings", torture disguised as "interrogation", secret detention, enforced disappearances and unfair military trials and special courts, including at the US-operated Guantanamo Bay facilities.
To address these concerns, the experts urged States to review their counter-terrorism laws and practices to comply with international human rights, humanitarian and refugee law.
Peace Bell remained silent
On 11 September 2001, UN Headquarters had been set to host the Secretary-General's annual ceremony to ring the Peace Bell , but as news of the severity of the attacks spread, UN staff reacted the same way as tens of thousands of other New Yorkers heading to the office.
"I saw the smoke, but I still went to the train station because I had to go to work," said Victor Evans-Harvey, who is now editor in chief of UN News.
'No, you can't go today'
"A UN security guard stopped me and said, 'where are you going?'" Mr. Evans-Harvey recalled. "I said, 'I'm going to work.' He said, 'No, you can't go today.'"
On the 37th floor of the UN Secretariat building, then Electoral Assistance Director Michelle Griffin had seen the first World Trade Center tower catch fire before even reaching her cubicle.
"As I was leaving for work, I heard my neighbour screaming, 'That's my office!'" she said. "I went outside and saw that huge gap in the first building."
Unity and solidarity
When the true severity of the attacks began to emerge, UN staff began evacuating along the stairwells. There was to be no ringing of the ceremonial bell that day - the International Day of Peace .
"As we evacuated, we could hear the news spreading down the stairs," Ms. Griffin said. "I remember hearing the Secretary-General's Chief of Staff and the Secretary-General's scheduler discussing whether to proceed with the Secretary-General's activities for the day as planned, including ringing the Peace Bell."
UN Spokesperson Stéphane Dujarric also recalled "a sense of panic" in the building.
"There were credible reports that another plane might be targeting the United Nations," he said, adding that decision was taken to keep then-Secretary-General Kofi Annan at his nearby residence.
In the days following the attacks, an unusual unity emerged within the United Nations, including the Security Council .
'Shockwaves still felt today'
For Mr. Dujarric, the seismic attacks triggered a long chain reaction, both inside and outside the UN.
"It was like an explosion, and the shockwaves from it can still be felt today," he said.
