A few days after the Taliban takeover of Afghanistan, a convoy of militants drove through the city of Idlib in northwestern Syria in cars bearing the group’s white-and-black flags, honking horns and firing their guns in the air.

The celebrations by an al-Qaida affiliate in a remote corner of war-torn Syria were an expression of the triumph felt by radical Islamic groups from the Gaza Strip to Pakistan and West Africa who see America’s violence-marred exit from Afghanistan an opportunity to reassert their presence.

For such groups, the chaotic US departure following the collapse of security forces it had trained for two decades is a gift, underlining their message that Washington eventually abandons its allies, and that defeating powerful armies is possible with enough patience.

“The success of the Taliban opens the way for radical groups to step up their recruitment operations globally. It is much easier for them now, and there is more receptivity,” said Hassan Abu Haniyeh, an expert on Islamic militants based in Amman, Jordan.

Despite the billions of dollars spent by the US and NATO over nearly 20 years to build up Afghan security forces, the Taliban seized nearly all of Afghanistan in just over a week amid the US troop pullout. The fundamentalist group swept into Kabul on August 15 after the Government collapsed and embattled President Ashraf Ghani fled the country.

Since then, tens of thousands of people desperate to escape a country governed by the Taliban have been trying to flee or already have been evacuated in a mammoth Western airlift.

“The events unfolding in Afghanistan have given jehadi groups and US adversaries reason to celebrate, and America’s allies in the region reason to feel anxious,” said Abu Haniyeh. “They now feel that America might drop them one day, same as it did the Government of Ashraf Ghani.”

There are concerns that Afghanistan will once again become a base for militants to plot against the West, much like the September 11, 2001, attacks that triggered the US invasion.

“This is the story that is going to impact and influence jehadi fighters around the globe for the next decade, the same way as the victory over the Soviets in Afghanistan in the ‘80s inspired the jehadis around the world during the whole 1990s and even afterwards,” said Elie Tenenbaum, director of security studies centre at the French Institute of International Relations.

In a twist, the Taliban victory also boosted the fortunes of their rivals in Afghanistan — a local branch of the Islamic State network. On Thursday, the affiliate claimed responsibility for the suicide attack that killed scores of people outside Kabul’s airport, including 13 US service members.

The Taliban now must contend with an emboldened ISIS, which is challenging their rule with militants that are far more radical. The group’s ranks have been bolstered after the Taliban freed prisoners during an advance through Afghanistan.

An editorial in the Islamic State group’s newsletter last week derided the Taliban, accusing them of collaborating with the US.

“America actually did it. They finally raised a ‘Mullah Bradley,” the editorial said, using a name it has coined for the Taliban in an apparent reference to the US fighting vehicle. The group also promised a new phase in its “blessed jehad” against the West.

Analysts say the Taliban’s success and the US withdrawal galvanises and gives a motivational boost to America’s adversaries and jehadi groups around the world.

Sayyed Hassan Nasrallah, the leader of Lebanon’s Shia militant group Hezbollah, said in a speech on August 27 that what is unfolding in Afghanistan “is a portrayal of America’s full defeat and the US demise and failure in the region.”

In northern Syria, a statement by Hayat Tahrir al-Sham, the al-Qaida affiliate there, said the Taliban victory proved no occupation can last forever. The leader of the radical Palestinian Islamic Hamas movement, which rules the Gaza Strip, congratulated the Taliban’s leader on the “demise of the US occupation.”

In Pakistan, the leader of Jaish-e-Mohammad, Mohammad Azhur, used the group’s publication to cheer the Taliban victory, saying it will inspire mujahedeen, or holy warriors, “the world over to continue their struggle for Islam.” The group’s fighters took credit for the 2019 attack in Kashmir that killed 40 Indian soldiers and brought the nuclear-armed neighbours to the brink of war.

Amir Rana, executive director of the Islamabad-based Pakistan Institute of Peace Studies, said the events in Afghanistan could inspire hard-line Sunni groups who are waging sectarian battles against Shia. The anti-Shia groups Lashkar-e-Janghvi and Sipah-e-Sahaba Pakistan have championed the Taliban victory, raising fears they could restart their deadly activities.

Heni Nsaibia, a senior Sahel researcher at the Armed Conflict Location & Event Data Project, said the Taliban takeover would be a motivational boost for extremists in West Africa, showing that patience and perseverance can pay off.

The biggest danger, according to the analysts, is in unstable countries with a weak Central Government and a history of insurgency, such as Iraq, Syria, Yemen and Libya.

There are echoes of 2014, when the ISIS group sprang from the chaos of conflicts in Iraq and Syria, seized a giant stretch of territory straddling both countries, and declared a “caliphate” after US-trained Iraqi forces collapsed. Terrorist attacks in Europe and beyond followed before ISIS was defeated in 2017, but attempts to regroup have been seen in the past two years, with new attacks in Iraq and Syria.

A report to the UN Security Council last week said the threat to international security from the ISIS is rising, pointing to an “alarming” expansion of its affiliates in Africa and its focus on a comeback in Syria and Iraq.

The report said ISIS and other terrorist groups have taken advantage of “the disruption, grievances and development setbacks” caused by the Covid-19 pandemic.

Abu Haniyeh, the analyst in Amman, said the perceived defeat of US forces in Afghanistan by a radical group is reverberating among frustrated individuals around the world and will have widespread ramifications in the coming years.

“It gives hope for extremist groups the world over,” he said.