September 8th, 2017 
(FINANCIAL TIMES) — By David Gardner
It is hardly news to the people of Barcelona and London, and before them the citizens of Paris and Brussels, Istanbul and Ankara, St Petersburg and Stockholm, or Nice and Berlin, that jihadis inspired and incited by Isis can terrorize their cities, even as an array of forces recaptures Isis strongholds in Mosul, Raqqa and, now, Deir al-Zor. The Islamic State caliphate, in all its monstrous vainglory, will perish. But jihadism, in all its blood-addled and doctrinal simplicity, would seem to have a fiery future.
Attacks like last month’s on Barcelona’s Ramblas, or at Westminster and London Bridge, are not, of course, new — nor purely a tactical riposte to territorial defeat in Syria, Iraq and elsewhere. Isis may be the first modern, Sunni jihadist movement to have set up a proto-state. But it always urged its followers to use the full gamut of irregular warfare, from classic terrorism and hit-and-run guerrilla insurgency to vans and knives. The world will now see more of this as the jihadis melt back into local Sunni Arab towns and tribes, and build their global networks and regional franchises.
Getting a good sense of their numbers is hard. But it is worth remembering that the precursor to Isis, the Iraqi chapter of al-Qaeda created by the sanguinary Abu Musab al-Zarqawi, was all but destroyed in 2007-09 by the US military “surge” and revolt of the Sunni tribes of central and western Iraq. Resurrected by Syria’s descent into sectarian carnage, and given new backbone by allying with the Sunni supremacist, residual power structure of Saddam Hussein’s Ba’ath party and army, Isis stormed back into Iraq to set up its caliphate five years later. Can it repeat this phoenix trick?
The war in Syria, now in its seventh year, has made Isis — at its core, Iraqi — a much bigger phenomenon than its al-Qaeda predecessor. Yet the question goes beyond Isis. Hayat Tahrir al-Sham, the latest iteration of the Jabhat al-Nusra movement spawned by al-Qaeda, now fields one of the biggest armies in Syria.
Although much of Tahrir al-Sham’s estimated 30,000-strong force is bottled up in Idlib province in the north, it has successfully annexed most rival Salafist fighting groups, controls a long strip of Syria’s north-west border with Turkey, has a plentiful supply of suicide-bombers and demonstrable offensive capacity. Unlike Isis, as the French Syria scholar Fabrice Balanche remarks, this group “practices discretion in order to avoid antagonizing locals” and, crucially, “relies more on the potency of its network than on the accumulation of territory”.