ISIS Caliphate Shrinks 14 Percent in 2015 as Syrian Kurds Gain

Shi'ite paramilitary fighters hold an Islamic State militant group (ISIS) flag, which they pulled down during victory celebrations, after returning from Tikrit in Kerbala, southwest of Baghdad April 4. Reuters/Mushtaq Muhammed

The Islamic State militant group (ISIS) lost more than a tenth of its territory in 2015 as offensive air and ground operations by the U.S.-led coalition, Syrian Kurdish fighters, Iraqi security forces and the Kurdish Peshmerga take their toll on the group's self-proclaimed caliphate, according to new research published on Tuesday.

The group lost 12,800 square kilometers (4,942 square miles) of territory since January 1, shrinking its total control of territory in Iraq and Syria by 14 percent to 78,000 square kilometers (30,115 square miles), the U.K.-based defense consultancy IHS Janes estimates, based on open-source intelligence and sources in Iraq and Syria. The figures reveal that the radical Islamist group's expansionist aims are being pegged back by a number of military operations .

The group has suffered a number of losses in both countries, despite gaining the cities of Palmyra in Syria and the provincial capital of the western Iraqi province of Anbar, Ramadi, in May. Iraqi forces ousted the group from Saddam Hussein's Iraqi hometown of Tikrit in April and Syrian Kurdish forces captured swathes of territory from the group in northern Syria, including the strategic city of Tal Abyad. However, the reduced size of the the group's caliphate still means that they control an area of land bigger than The Netherlands and Belgium combined.

IHS Janes ISIS Caliphate
The militant group's territorial losses in 2015. IHS Janes

"We had already seen a negative financial impact on the Islamic State due to the loss of control of the Tal Abyad border-crossing prior to the recent intensification of airstrikes against the group's oil production capacity," said Columb Strack, senior Middle-East analyst at IHS.

"Other substantial losses in Iraq include the city of Tikrit, the fiercely contested Baiji refinery complex, and a stretch of the main highway between Raqqa and Mosul, which complicates the transfer of goods and fighters between the two largest ISIS-controlled cities," he adds.

While ISIS lost territory every month in 2015, Syrian Kurds were "by far the biggest winners" of the year, taking control of all of Syria's traditionally Kurdish territory, expanding by 186 percent to 15,800 square kilometers (6,100 square miles). The Syrian government controls an estimated 30,000 square kilometers (11,583 square miles), representing a loss of 16 percent in 2015, while the Iraqi government regained six percent of territory and the Iraqi Kurds two percent, according to IHS.

In order to capture Ramadi and Palmyra, the group had to bring fighters from the frontline battles against the Kurds in northern Syria, a sign of the group's operational weaknesses as it continues to place as much territory under its radical interpretation of Islamic law, Strack says.

"This indicates that the Islamic State was overstretched, and also that holding Kurdish territory is considered to be of lesser importance than expelling the Syrian and Iraqi governments from traditionally Sunni lands," he continues. "The Kurds appear to be primarily an obstruction to the Islamic State, rather than an objective in themselves."

Iraqi forces have launched an offensive to recapture Ramadi, entering the city and retaking a number of key districts. The governor of Anbar's office told Newsweek last week that the city would be liberated "by Christmas." If the ISIS-held city is to fall, it would represent the biggest success for the Iraqi forces and the biggest defeat for the militant group since it swept across Syria and Iraq capturing territory in June 2014.