What has its territorial defeat accomplished?
IS’ possession of land in Iraq and Syria set it apart from other like-minded groups such as al Qaeda and became central to its mission when it declared a caliphate in 2014, claiming sovereignty over all Muslim lands and peoples.
The destruction of the quasi-state it built there has denied the group its most potent propaganda and recruiting tool as well as a logistical base from which it could train fighters and plan coordinated attacks overseas.
It also freed its former subjects from summary executions and draconian punishment for breaking its strict laws or, for some minorities, sexual slavery and slaughter.
Warfare wiped out thousands of its fighters. And, financially, its defeat deprives it of greater resources than any modern jihadist movement has enjoyed, including taxes on its inhabitants and the proceeds of oil sales.
Syrian soldiers patrol at the Yarmouk Camp district in south Damascus, Syria, 22 May 2018. Source: AAP
What threat does IS still pose in Iraq and Syria?
In its previous guise as an al Qaeda offshoot in Iraq a decade ago, IS navigated adversity by going underground, biding its time to rise suddenly again.
Since suffering devastating territorial losses in 2017, IS has steadily turned again to such tactics. Sleeper cells in Iraq have staged a scatter-gun campaign of kidnappings and killings to undermine the Baghdad government.
The group has also carried out many bombings in northeast Syria, which is controlled by U.S.-backed Kurdish forces, including one that killed four Americans in January. Kurdish and U.S. officials say it remains a menace there.
READ MORE:
Wounded and alone, children escape IS
In Syria, IS fighters are on the brink of losing their last foothold of Baghouz at the Iraqi border. But they still have a presence in sparsely populated territory west of the Euphrates River in an area otherwise held by the Syrian government.
What has happened to its leaders, fighters and followers?
The fate of the IS leader, Abu Bakr al-Baghdadi, remains a mystery. The U.S. government’s top experts strongly believe he is alive and possibly hiding in Iraq, U.S. sources recently said. Other top-echelon leaders have been killed in air strikes.
Thousands of IS insurgents and civilian followers have also been killed and thousands more captured. An unknown number remain at large in both Syria and Iraq.
Iraq is putting on trial, imprisoning and often executing IS detainees. The U.S.-backed Syrian Democratic Forces (SDF) holds many hundreds of IS fighters and followers.
Ahead of the final assault on Baghouz, the SDF said it had 800 foreign fighters and more than 2,000 IS wives and children in its hands. The SDF has evacuated a large number of IS followers from Baghouz, so these numbers are now higher.
Civilians evacuated from the IS group's embattled holdout of Baghouz wait at a screening area held by the SDF in eastern Syria on February 27, 2019. Source: Getty Images
Many low-level local operatives have been released in Syria.
The SDF complains that Western states are reluctant to take back the foreign fighters, who are widely seen as a security threat at home but who might be hard to legally prosecute.
Can it still organise or inspire attacks overseas?
As IS clung to its last scrap of land, the head of Britain’s spy agency MI6 warned that the group would return to “asymmetric” attacks.
Even after it began losing ground militarily, IS still claimed responsibility for attacks made in different countries, though often these have been blamed on “lone wolves” without its direction.
It started years ago to call on followers abroad to plan their own attacks, rather than focusing purely on ones staged by trained operatives supported by the group’s hierarchy.
In early 2018 the head of U.S. military central command said IS was resilient and remained capable of “inspiring attacks throughout the region and outside of the Middle East”.
What does its fall mean for the future of global jihad?
Although IS' core territory was in Iraq and Syria, jihadists fighting in other countries, notably Nigeria, Yemen and Afghanistan, pledged their allegiance to it.
Whether those groups will still wear its mantle, especially if Baghdadi is captured or killed, is an open question, but there seems little chance they will soon end their campaigns.
Al Qaeda also retains numerous franchises around the world, and other militant Islamist groups operate in countries where normal governance has broken down.
U.S.-backed Syrian Democratic Forces fighters in the desert outside Baghouz, Syria, Wednesday, Feb. 27, 2019. Source: AP
Jihadist ideology has long proven itself able to mutate as circumstances change, and there is no shortage of warfare, injustice, oppression, poverty, sectarianism and naked religious hatred for Islamist militants to exploit.
