The caliphate of Islamic State has ended. Its effect lasts.

Father and son Sajid and Navid Akram, who Australian officials say 15 people attending Hanukkah celebrations along the beach died On Sunday, they brought homemade Islamic State flags along with improvised explosive devices in their car, police said.

Australian intelligence officials investigated son Naved in 2019 for suspected ties to a cell inspired by the extremist group. Authorities are investigating the travel undertaken by the two men last month islands in the philippines Where local rebels had previously sworn allegiance to the Islamic State.

The group, operationally a largely spent force, relies on a sophisticated propaganda machine to recruit fighters that relies mostly on a nexus of dark-web servers, viral social-media postings and artificial intelligence, experts say.

“The online sphere is 100% important for these attacks,” said Hans-Jakob Schindler, former coordinator of the UN Security Council panel on Islamic State and al Qaeda.

“The Internet is all about outrage. It’s perfect for the extremism of IS that is based on grievances,” he said, using the acronym for the group.

Over the past five years, 93% of deadly terrorist attacks in the West were carried out by lone-wolf actors, according to the think tank Institute for Economics and Peace.

Islamic State emerged in Syria and Iraq in 2014, where it captured vast areas before being almost completely destroyed in a US-backed counterterrorism campaign five years later.

took responsibility for attack in syria Over the weekend, a lone gunman killed two American soldiers and an American civilian.

In recent years in the US and Europe, so-called lone-wolf attackers have often claimed to be acting on behalf of the group. Authorities have said most or all of them were radicalized online and had no affiliation with any organization.

This marks a significant change from the group’s early days, when large-scale attacks were carried out by veterans of its violence campaign in parts of the Middle East. The perpetrators of the serial attacks that killed 130 people in Paris in November 2015 were fighters from Islamic State in Syria.

person responsible for a fatal incident Vandalism and knife attack on a synagogue Before being shot by officers in Manchester, England, in October, he called emergency services from the scene while declaring allegiance to Islamic State, British police said. He said he was influenced by “extreme Islamic ideology”.

The attack, along with Sunday’s attack on Bondi Beach, shows how Islamic State followers have drawn a link between their violent acts and Israel’s war against Hamas in Gaza. More than 70,000 Palestinians have been killed and more than 171,000 wounded in the conflict, according to health officials in the Palestinian enclave, who did not say how many were among the fighters. The war began after deadly Hamas-led attacks in southern Israel left nearly 1,200 people dead and 250 taken hostage by the group and its allies.

Islamic State and other jihadists “have attempted to capitalize on the conflict between Israel and Hamas, positioning it within broader global jihadist narratives to align with their terrorist agenda,” Britain’s Intelligence and Security Committee said in a parliamentary report published on Monday. “It is highly likely that individuals will continue to be encouraged to carry out attacks.”

Attacks inspired by Islamism remain by far the largest source of political violence in Europe, although far-right terrorism is on the rise. According to Europol, the EU’s law-enforcement agency, jihadist-related acts were to account for 64% of all terrorism cases on the continent in 2024, down from 74% the previous year.

In a speech in September to mark the end of his tenure as head of MI6, the UK’s foreign intelligence service, Richard Moore said, “The threat has come more from domestic, self-radicalised lone operators via keyboard – a diffuse and networked threat.”

Most online platforms had expelled Islamic State after it first emerged on the world stage in 2014. But Mustafa Ayad, executive director of the Institute for Strategic Dialogue, a nonprofit that monitors extremist online content, said the group has become adept at shape-shifting to avoid the crackdown.

Tech Against Terrorism, a U.N.-backed organization that works with tech companies and governments to crack down on extremist content online, said much of its content exists on password-protected websites, on data storage platforms that remain largely anonymous.

Last year a joint investigation by Spanish authorities, the Federal Bureau of Investigation and Europol seized computer servers in Germany, the US and Iceland that stored Islamic State material, including bomb-making manuals and cryptocurrency wallets.

Ayad said supporters typically create new accounts as older accounts are deleted and scrub the text of references to the group, or remove its logo, to avoid identification.

Footage of an attack claimed by Islamic State outside Moscow in 2024 that killed 137 people, according to the ISD, has been shared on social-media platforms

Islamic State has also tried to take advantage of TikTok’s reach to radicalize and recruit youth, according to a July UN counterterrorism report.

When Islamic State inspired attackers Mob attacked in New Orleans He posted footage of the attack on Facebook, killing 15 people on New Year’s Day this year. The ISD said the video was shared widely on TikTok, where posts glorifying the attacker were viewed thousands of times. Schindler, a former UN counter-terrorism official, described police content as a “gross failure of the platforms” for the rapid dissemination of such footage.

Facebook’s owner, Meta Platform, said it had removed all content posted by the criminal and those praising his actions. “Islamic State and all associated organizations are banned from our platform,” the company said, adding that it often “sees examples of groups or individuals adopting new tactics to circumvent and avoid our policies and enforcement.”

TikTok said it removed more than 6.5 million videos in the first half of this year for violating its rules against violent and hate organizations. It said it took down 17 networks promoting violent extremism online in 2025, including more than 920 accounts.

According to a February UN report, the number of youth recruiting for Islamic State is declining. It cited the arrest of a 19-year-old suspect suspected of planning an attack during a Taylor Swift concert in Vienna, Austria last year, as well as the arrest of an 18-year-old Chechen detained in France over an attempt to attack an Olympic football match. Security forces across Europe also arrested 25 minors last year who were part of online groups linked to Islamic State as they planned coordinated attacks in multiple cities.

Online grooming often begins with general promotion before moving on to precise instructions for the attacks. A Syrian refugee who stabbed three people to death in northern Germany last year initially consumed Islamic State-related material online before being radicalized by the war in Gaza, Schindler said.

He said the man then connected with Islamic State supporters online and spread extremist material. Acting on advice from a group available online, he bought a kitchen knife — rather than drawing the attention of authorities — and stabbed the victims in the neck to increase the chances of them dying, said Schindler, now senior director at the Counter Extremism Project, a nonprofit that counters extremist ideologies.

Islamic State is also increasingly using AI tools to automatically translate propaganda, according to a UN counterterrorism report. Group members in Central Asia are using AI to create improvised explosive devices from household materials and spread instructions for 3-D printing weapon components. The content is then broadcast on Telegram and WhatsApp messaging apps. Neither company responded to requests for comment.

Write to Benoit Faucon here benoit.faucon@wsj.com