In the first nine months of 2016, IS's territory fell from 30,115 sq miles to 25,290 sq km. However, IS losses slowed in the three months before October to just 1,080 sq miles.
The slowdown appears to coincide with Russia reducing the number of air strikes against IS targets.
Experts say that the losses the group has sustained are still significant. IS has been pushed back 10km from the Turkish border, and it lost the Syrian city of Manbij and its surrounding roads, which linked the Turkish border to IS's de-facto capital Raqqa. Iraqi forces have secured Qayyarah Airbase, a key strategic facility 60km south of the IS stronghold of Mosul.
“The Islamic State's territorial losses since July are unprecedented in their strategic significance,” said Columb Strack, senior analyst and head of the IHS Conflict Monitor.
“The loss of direct road access to cross-border smuggling routes into Turkey severely restricts the group's ability to recruit new fighters from abroad, while the Iraqi government is poised to launch its offensive on Mosul.”
If the much-delayed offensive against Mosul – expected to begin later this month – succeeds, it would be a huge blow to the IS terrorists.
Authorities in Baghdad say regaining Mosul would spell the end for the group in their country.
