ISIS has expanded largely by ensuring the support of Sunni tribal factions in both Iraq and Syria. Those times when a tribe has turned on them, they’ve been ruthless, killing huge numbers in retaliation.
Today, with ISIS expected to soon make another push for the central Iraqi city of Tikrit, the militants have rounded up an estimated 100 Sunni tribesmen from the area.
They weren’t capturing people at random, according to reports, they were breaking into their homes and checking their cellphones for any evidence they might be on the side of the Iraqi government.
The US has been keen to get Sunni tribals who are anti-ISIS back on the side of the Shi’ite-dominated government, and ISIS is apparently quite aware of this risk, and is trying to get potential tribal opponents off the battlefield before they attack Tikrit this time.