ISIS’s total ranks have dwindled to about 15,000 remaining fighters, with most of them outside of the group’s two major cities, though it has kept a hold on more rural population centers along the Euphrates River, according to the US-led coalition. A defense official, speaking on background during a Wednesday briefing with reporters, said Combined Joint Task Force-Operation Inherent Resolve estimates that about 2,500 fighters remain in Western Mosul locked in a fight with Iraqi Security Forces and cut off from the rest of the group. About 3,000-4,000 fighters are in the group’s self-proclaimed capital of Raqqa, Syria. The remaining fighters are in smaller population centers along the Euphrates River. Although they have not been able to travel freely up and down the river, they have created a “ferry system” to try to move supplies.
ISIS still have oil production facilities, including ones located near Palmyra and Deir Ezzor where it can still bring in funding. The group’s coffers are depleting, though the official said ISIS has been able to save on payroll as more and more of its fighters are killed. The flow of foreign fighters to the group has continued to drop, to about 100 or fewer per month, as it has become harder to travel through Syrian-held territory to the West and Kurdish-held territory to the East to the group’s remaining land. Also, there’s a “diminished appeal” to join the group in its territory, which has faced increased pressure, the official said. The coalition believes the group’s leader Abu Bakr al Baghdadi long ago left Mosul before the city was cut off by Iraqi forces and coalition air support, though the official did not say if the coalition knows where he is or whether it’s tracking him. That job falls to other agencies, such as US Special Operations Command. The coalition has determined it to be more tactically important to target field-level commanders and in turn impact ISIS’s ability to operate on the battlefield, said the official.
The current estimate of 15,000 fighters means the coalition and allied forces have killed more than half of ISIS’s fighters since its peak. The group has also lost about 65 percent of its total territory since that peak, largely in Iraq where security forces have been effective in regaining cities and open territory. In Mosul, about a half million people have been freed with thousands returning to their homes in the eastern half of the city. Schools and markets also are reopening, the official said.