An Iraqi soldier stands next to a wall with a red cross drawn through a slogan of the Islamic State (IS) group, in Fallujah
Beirut (AFP) - Despite major setbacks including the loss of access to the Syria-Turkey border and the assassination of several top leaders, the Islamic State group remains a potent force, analysts warn.
The increasing pressure on IS, including Turkey's decision to launch an operation against it in northern Syria, has seen the organisation lose ground at an unprecedented pace.
But the jihadist organisation still has the capacity to obtain weapons, attract recruits and dispatch fighters to carry out devastating attacks abroad, according to experts.
On Sunday, the Turkish operation reclaimed the last stretch of the Syria-Turkey border from the jihadist group, sealing off its self-styled "caliphate" in Syria and Iraq and forcing it to rely on smuggling networks instead.
It was just the latest setback for IS, which is now under attack from Syrian and Iraqi troops, but also Kurdish fighters, Syrian rebels, Turkish forces, Russian warplanes, and a US-led coalition.
IS now controls just 20 percent of Iraq and 35 percent of Syria, according to Fabrice Balanche, an expert on the political geography of Syria.
At the height of its expansion after seizing Syria's Palmyra in May 2015, it controlled around 240,000 square kilometres (more than 92,000 square miles) in both countries, an area roughly the size of Britain, he says.
But today that has fallen by more than a third to around 150,000 square kilometres, Balanche says.
The population it controls has dropped from some eight million people in mid-2015 to 4.5 million people today, he says.
Last month, the jihadists lost Jazirat al-Khaldiyeh, an area in Iraq's western Anbar province that was a key crossroads, dealing a major blow to its mobility.
And in Libya, the group is on the verge of losing its stronghold of Sirte.
The territorial losses have been accompanied by a series of high-profile assassinations of its key leaders, including senior commander Omar al-Shishani, and spokesman and top strategist Abu Mohamed al-Adnani.
- 'Shouldn't be underestimated' -
The setbacks paint a picture of decline for IS, once deemed the world's richest "terror" group, able to attract a flood of foreign recruits with its army-like prowess and a pledge to "remain and expand".
But analysts warn the group is far from finished, and that its focus may simply be shifting from territorial expansion to consolidation of population centres -- like Syria's Raqa and Iraq's Mosul -- and new attacks against civilians in the region and the West.
"IS has faced a campaign of exponential pressure that has steadily constrained their capacity to fight, to operate, to earn and to credibly claim an 'expanding' caliphate," said Charles Lister, a senior fellow at the Middle East Institute think-tank.
"But it remains a highly adaptable organisation with extensive asymmetric reach -- it should not be underestimated."
While the loss of the border with Turkey will hamper the group's ability to import new weapons and recruits, as well as to export resources such as oil, that challenge is hardly new.
"IS's access to the border has been dramatically reduced for a while now," said Syria expert Thomas Pierret, a lecturer at the University of Edinburgh.
Pressure from Kurdish forces and a Turkish crackdown on the border had already forced IS to mainly rely on smuggling networks instead, he said.
And for weapons, it has always relied to some degree on purchasing from corrupt individuals among its enemies, or capturing arms from defeated opponents.
"All of that will certainly be sufficient to ensure the group's survival as an insurgency, but keeping afloat a proto-state in these circumstances will become more problematic," Pierret said.
- 'Uptick in terror attacks' -
Given that difficulty, IS is likely to continue a trend experts say is already under way: "consolidating core urban, populated territory and rebuilding the asymmetric capabilities that allow it to carry out incessant bombings", Lister said.
IS still holds the key cities of Raqa and Mosul, with long-running talk of operations to recapture them yielding little in the way of military action so far.
In the interim, the group has claimed a steady trickle of attacks in the West, including the shooting of two police officers in Copenhagen last week, and unleashed a wave of suicide bombers in Syria and Iraq.
On Monday IS claimed a series of bombings across mostly government-held Syria that killed at least 48 people, as well as a car bomb in central Iraq that killed at least seven.
"The trajectory is characterised by an overall downward trend in military influence and ability to preserve its territory in Libya, Iraq and Syria, along with an uptick in launching terrorist operations against civilian targets," said Charlie Winter, an associate fellow at the Hague-based International Centre for Counter-Terrorism.
The shift has already been reflected in IS's media output, said Aymenn al-Tamimi, a jihadism expert at the Middle East Forum.
"We see this in the overall decline in non-military-related IS propaganda, along with a lack of claims of new 'wilayas' (provinces) abroad, but focus instead on claiming attacks," he said.
That leaves IS looking like a different, but still dangerous, force, said Winter.
"I think we have seen it at its strongest militarily, but in terms of overall influence... it is still a great cause for concern."