IT could well be an ominous harbinger of things to come, say some security experts. As Russia reels from the largest loss of life in a terrorist attack in the country in at least 10 years, it brought back memories of those Islamist insurgencies that marked the first decade of President Vladimir Putin’s rule.

In a world currently beset by major conflict and crises, it’s easy to forget the threat that jihadist groups posed, making international headlines only a few years ago.

But that threat was again brought into sharp focus this weekend after a ­minimum of four camouflage-clad ­gunmen burst into the Crocus City Hall concert venue in Krasnogorsk on the ­outskirts of ­Moscow before opening fire with automatic ­weapons, killing at least 115 people and injuring more than 145 in an attack claimed by Islamic State (IS) group terrorists.

The National: In this photo released by the Russian Emergency Ministry Press Service on Saturday, March 23, 2024, Russian Emergency Ministry rescuers work inside the Crocus City Hall on the western edge of Moscow, Russia, Saturday, March 23, 2024, following an attack

Almost immediately, Russia’s ­national guard said a “search is ongoing for the ­attackers” who, according to the state newswire service RIA Novosti, left the ­venue in a white Renault. But late ­yesterday, Russia’s Federal Security ­Service (FSB) said four people involved in the Moscow ­attack were among 11 ­detained.

But despite the arrests, questions ­persist over why the Kremlin appeared to ignore earlier intelligence warnings flagged up and shared by the US that indicated a heightened threat posed by “extremists” with imminent plans for an attack on “large gatherings” in Moscow.

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In addition to publicly warning on March 7 about a possible attack, US ­officials said they had privately told ­Russian officials about the intelligence pointing to an impending attack. It is not clear how much information the ­Americans gave Russian officials beyond what was in the public warning.

But in a speech during his annual ­address to his most senior spies on March 19, Putin rounded on the American ­warnings, calling them “provocative.”

“All this resembles outright ­blackmail and an intention to intimidate and ­destabilise our society,” Putin was ­reported as saying.

The Russian leader’s stance came ­despite Russian authorities having ­reported several ISIS-related incidents within the past month. For its part, the FSB has said it had recently broken up an IS cell in Kaluga, a city south-west of Moscow and on March 7 said it had foiled an attack on a Moscow synagogue. On March 9 two Kazakh citizens were also reportedly killed in a shootout with ­anti-terrorism officers.

Putin’s stance only emboldened some Russian politicians, who, without any evidence, speculated that Ukraine was to blame for Friday’s concert venue ­attack. It was an accusation immediately ­rebuffed by the Ukrainian government which, ­according to reports in The Economist citing a “high-level intelligence source”, said that Kyiv had been worried that the Kremlin might try to weaponise a ­terror event of this sort, especially as Putin weighs up whether to risk a new wave of mobilisation.

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The same source quoted by The ­Economist told the magazine that “it would be an act of pure insanity for Ukraine to attempt anything of the sort. Killing civilians would be a sure way to alienate the Western supporters on whom Ukraine so heavily depends”.

Mykhailo Podolyak, a senior ­adviser to Ukrainian president Volodymyr ­Zelenskyy was also quick to refute any claim of Ukrainian involvement. ­Speaking to journalists, he said that “­everything in this war will be ­decided only on the ­battlefield. Only by the ­quantity of ­weapons and qualitative ­military ­decisions. Terrorist attacks do not solve any problems.”

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But as Kyiv waited to see how the ­Kremlin would officially classify the ­Moscow attack, Islamic State in ­Khorasan Province (ISIS-K), an Afghan affiliate of IS, openly claimed responsibility for the attack in a statement posted on its official Amaq news agency.

It said its fighters had attacked on the outskirts of Moscow, “killing and ­wounding hundreds and causing great destruction to the place before they ­withdrew to their bases safely” and then escaped. It gave no further detail. ­Western intelligence assessments ­appear to ­confirm that they believe ISIS-K ­carried out the assault on the Crocus City Hall.

“ISIS-K has been fixated on Russia for the past two years,” frequently ­criticising Putin in its propaganda, said Colin P Clarke, a counterterrorism analyst at the Soufan Group, a security consulting firm based in New York.

“ISIS-K accuses the Kremlin of having Muslim blood on its hands, referencing Moscow’s interventions in Afghanistan, Chechnya and Syria,” Clarke added, in an interview with The New York Times.

Other experts agree with this ­assessment. Michael Kugelman of the Washington-based Wilson Center said that ISIS-K “sees Russia as being ­complicit in activities that regularly ­oppress ­Muslims”.

He told Reuters that the group also counts as members of a number of Central Asian militants with their own grievances against Moscow.

But while the latest deadly attack has thrown ISIS-K into the global spotlight, who exactly are they, what relationship do they have along with other affiliates to IS’s core and do they pose a threat ­elsewhere, including here in the West?

It was back in 2015 when disaffected members of the Pakistani Taliban as well as Afghan Taliban, and the Islamic ­Movement of Uzbekistan, who embraced a more extremist and violent version of Islam, founded ISIS-K.

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The “K” in ISIS-K denotes Khorasan, an old term for the region that included parts of Iran, Turkmenistan, Pakistan and Afghanistan.

By 2021, however, the group saw its manpower reduced by a combination of American airstrikes and Afghan special forces raids, during which many of its leaders were killed. But after the Taliban toppled the Afghan government that same year and the US military withdrew from the country, ISIS-K saw a resurgence, meaning it posed not only a big threat to the Taliban’s ability to govern but raised its international profile.

According to a report by the Centre for Strategic and International Studies, ISIS-K maintains a core group of 1500 to 2200 fighters in the Nangarhar and Kunar ­provinces of Afghanistan, with smaller cells dispersed across the country.

Distinct from the Taliban, whose ­focus is primarily domestic, ISIS-K ­operates within the broader IS network, ­aiming to execute assaults on Western, ­international, and humanitarian entities globally. The group’s attack in Moscow is only the latest in which it has proved its lethality.

Iran in January saw one of its most high-profile strikes since August 2021, when an ISIS-K suicide bomber killed 13 US Marines and some 170 Afghan ­civilians at the Kabul airport during America’s tumultuous military withdrawal from ­Afghanistan.

The Iran attack killed nearly 100 ­people in a series of suicide bombings in the ­Iranian city of Kerman during a ­ceremony marking the death of Iranian Major General Qasem Soleimani.

Even though US-Iranian relations have been in a deep freeze, the Biden ­administration is said to have tried to give Iran a heads-up as it did with Russia this month, under what is known as the ­“duty-to-warn” information sharing on transnational terrorist threats.

In a recent analysis published on the online portal The Conversation, ­Clemson University scholar Amira Jadoon and US Military Academy at West Point, ­Professor Nakissa Jahanbani said of that attack in Iran that it, “highlights the ­success of ISIS-K’s recruitment strategies and its growing ability to strike declared enemies and undermine regional ­stability”.

Both scholars detailed how ever since the Taliban takeover in Afghanistan, ­ISIS-K has sought to “internationalise its operational and recruitment campaign”.

“Utilising a sweeping propaganda ­campaign to appeal to audiences across South and Central Asia, the group has tried to position itself as the dominant regional challenger to what it perceives to be repressive regimes,” the analysts noted.

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This process of internationalising ­ISIS-K’s agenda, they say, involves the group targeting regional countries ­directly, or their presence within ­Afghanistan. There is also a desire to strike US and Western interests.

Speaking recently before a House ­committee, US General Michael E ­Kurilla, the head of the military’s Central Command, warned that ISIS-K “retains the capability and the will to attack US and Western interests abroad in as little as six months with little to no warning”.

Counterterrorism officials in Europe say that in recent months, they have ­already neutralised several nascent ­ISIS-K plots to attack targets there.

But intelligence and security experts say it’s important also to look at ISIS-K within the context of the Islamic State group as a whole, not least given it represents only one affiliate.

In March last year, the Washington ­Institute for Near East Policy a think tank based in the US, launched what it called its Islamic State Select Worldwide ­Activity Map, aimed at tracking and ­better ­understanding the global ­jihadist ­organisation’s status. This ongoing ­project includes data on IS propaganda, claims of responsibility over attacks, ­financial ­sanctions, arrests, and other ­factors giving a broader view of IS.

After only a year of garnering such ­material, the institute says the data “paints a sobering picture”.

It outlines how although the core IS “provinces” in Iraq and Syria ­remain ­degraded, “the group has been able to ­diversify at the periphery, with the ­Khorasan Province in Afghanistan ­(ISIS-K) spearheading external ­operations while various other provinces establish territorial control in Africa”.

Led today by the relatively little-known Abu Hafs al-Hashimi al-Qurashi, IS ­continues to claim attacks regularly in places as far flung as Afghanistan, ­Democratic ­Republic of Congo, Egypt, Iraq, ­Mozambique and Syria.

As the institute’s data reveals, since this time last year, the IS central media administration has claimed responsibility for 1121 attacks which killed or injured 4770 people.

“Most of these claims were issued by the West Africa province,” (ISWAP) based primarily in Nigeria and southeast Niger, followed by IS provinces in Syria, Iraq, Central Africa, and Mozambique. ISIS-K had the most damaging attacks on ­average, the data revealed, claiming around 14 casualties per incident.

Further detailing the extent to which ISIS-K has gone global, beyond attack plotting, the Institute’s reports indicate that the authorities in various countries have also arrested ISIS-K members and supporters for recruiting and ­fundraising on a number of occasions since 2020, ­including Britain, India, Turkey, ­Pakistan and the United States.

It concludes that “ISIS-K plots should be considered the organisation’s biggest global threat today”, with the Afghan ­affiliate in the past year having planned 21 external plots or attacks in nine ­countries, compared to eight plots or ­attacks in the previous year and just three between 2018 and March 2022.

This weekend, as Moscow comes to terms with the terrorist attack, the ­Kremlin continues to use the situation to bring pressure on Ukraine. Yesterday, the FSB claimed that the terrorists involved were planning to cross the border with Ukraine and that they had “contacts” on the Ukrainian side.

Calling the accusation “absurd”, a spokesperson for the Ukrainian military intelligence directorate – Andriy ­Yusov – stressed that the border area with Ukraine is “full of special services and military. Also, the latest events in ­Belgorod ­region and Kursk – where there is military ­activity – mean this is a frontline.

“To suggest the suspects were ­heading to Ukraine would suggest they were ­stupid or suicidal,” Yusov added in ­response to Russian claims that few security analysts take seriously.

Stoking the geopolitical fallout ­further, Russian Security Council deputy ­chair, Dmitry Medvedev, has also been quick to point the finger at Ukraine.

“If they establish that these are ­terrorists of the Kyiv regime, they must all be found and mercilessly destroyed. Including ­officials of the state that ­committed such atrocity,” the former Russian president said of the attack.

Suddenly, it seems, Friday’s events have the capacity to escalate an already dangerous situation between Russia and Ukraine, while few doubt that IS and its leaders have achieved even more than they bargained for by adding to the instability.

As transnational jihadist terrorism once again rears its head, the need has never been greater for global vigilance over the activities of IS and its affiliates. The ­evidence is there and the attack in ­Moscow is the barbaric and bloody proof – even if the Kremlin, for now, chooses not to recognise it.