Australia’s domestic intelligence chief warned that international terrorism is again a significant security concern as Australians joined commemorations marking 25 years since the Sept. 11 attacks in the United States.
Australian Security Intelligence Organisation Director-General Mike Burgess said al-Qaida, the Islamic State group and their affiliates were exploiting loosely governed territories and online platforms to expand their capabilities.
“Twenty-five years later, transnational terrorism has re-emerged as a significant, malignant security concern,” Burgess said Friday.
“These groups still see Western interests as legitimate targets,” he said, adding that they had demonstrated a renewed ability to carry out or inspire attacks beyond their immediate areas of influence.
Burgess said ASIO had disrupted 33 major terrorism plots since 2014 in which an attack was imminent or planning was advanced. Sixteen were disrupted after the Bondi mass shooting in December 2025, he said.
The alleged cases included plans for an antisemitic attack, threats to kill Muslims and an advocate of racist violence who was allegedly found with weapons and ammunition.
Burgess said Sunni violent extremism continued to make up most of ASIO’s terrorism caseload, but the threat had become more diverse since 2001. Large, sophisticated attacks had increasingly given way to individuals or small groups using basic weapons and tactics, making plots harder to detect.
“ASIO is not all-seeing and all-knowing. And we do not want to be,” he said. “We cannot stop every terrorist, just as we cannot catch every spy. But we will continue to work around the clock to keep Australians safe.”
The warning came as ceremonies were held across the United States to remember the nearly 3,000 people killed on Sept. 11, 2001, when al-Qaida terrorists hijacked four passenger planes and attacked New York and the Pentagon. A fourth plane crashed in a field near Shanksville, Pennsylvania, after passengers and crew members fought the hijackers.
To remember the lives of the 2,977 people killed in the 9/11 attacks 25 years ago, 2,977 drones were arranged in the shape of the original Minoru Yamasaki-designed World Trade Center at full architectural scale for a stunning temporary memorial.
President Donald Trump and first lady Melania Trump attended a ceremony at the Pentagon, where the names of the 184 people killed there were read aloud. Earlier, Defense Secretary Pete Hegseth and senior military officials watched as a giant American flag was unfurled over the section of the building struck by a hijacked plane.
Vice President JD Vance attended the commemoration in New York alongside former presidents George W. Bush, Bill Clinton, Barack Obama and Joe Biden. Administration officials also attended a ceremony in Shanksville.
For Australia, the anniversary recalled a decisive moment in its alliance with the United States.
Former Prime Minister John Howard was in Washington for talks with Bush when the attacks occurred. Howard told ABC Radio he had been preparing for a news conference when his press secretary told him a plane had hit the World Trade Center.
“I thought little more about it,” Howard said. His press secretary returned after the second plane struck.
“We knew then it wasn’t an accident, it was something worse,” he said.
News that another plane had hit the Pentagon emerged while Howard was holding the news conference, with smoke visible from the site. He was later taken to a bunker at the Australian Embassy as the attacks unfolded.
Australia subsequently invoked the ANZUS defense treaty for the first and only time in its history. The move helped underpin Australia’s involvement in the U.S.-led war in Afghanistan.
Howard, now 87, said he had no regrets about joining the military campaign, although he was unhappy with aspects of the eventual withdrawal from Afghanistan.
The attacks were an unparalleled event during his time as prime minister and shattered any belief that the world was free from the threat of terrorism, he said.
“It meant that the world would never be the same,” Howard said. “It was an entirely new and different and horrifying and terrifying world.”
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