ISIS will no longer exist as a state entity in Iraq/Syria by the end of 2017.

'State entity' means that ISIS held and governed territory with populated towns or cities as a territorial proto-state. True: by 31 December 2017, ISIS no longer governed any populated towns or cities in Iraq or Syria, for example after the loss of Mosul, Raqqa and its remaining urban strongholds, and credible sources (governments, the anti-ISIS coalition, major news outlets, conflict monitors) describe its territorial 'caliphate' as having collapsed. Mostly true: the proto-state had collapsed and all major cities were lost, but ISIS still held small remnant pockets (villages, desert areas) that sources describe as residual holdouts rather than a functioning state. Mixed: by the end of 2017 ISIS still governed a meaningful populated enclave, such as a cluster of towns in the Euphrates valley, but had lost most of its territory. Mostly false: ISIS kept substantial governed territory, including at least one significant town or city, with its administration largely intact. False: ISIS still governed major cities such as Raqqa or Mosul at the end of 2017.

Set before the research began.

1. E1 ISIS After the Caliphate Wilson Center · 28 November 2017

   “By November 2017, the ISIS caliphate had imploded after the loss of 98 percent of its territory.”

2. E2 Has ISIS Really Been Defeated? Pacific Standard (republished from Syria Deeply) · 22 December 2017

   “Militants also control at least 18 towns and villages in Deir Ezzor province, where it is battling both the Syrian government and the U.S.-backed Syrian Democratic Forces.”

3. E3 Islamic State 2019: An Assessment Military.com · 25 January 2019

   “By the end of 2017, Islamic State forces in eastern Syria had been largely reduced to an 80-mile strip of the central Euphrates Valley running southeast from Deir ez-Zor to Al-Bukamal, just north of the Iraqi border.”

4. E4 Last Iraqi town held by ISIS recaptured, officials say CBS News · 17 November 2017

   “The last urban areas controlled by the militants in Syria are parts of the border town of Boukamal and a patch of territory near the capital, Damascus, and in central Hama province.”

E1 reports that by November 2017 the ISIS caliphate had collapsed after losing 98 percent of its territory, and E4 says the last Iraqi town held by ISIS was retaken in November 2017. However, E2 (22 December 2017) reports that ISIS still controlled at least 18 towns and villages in Syria's Deir Ezzor province. E3 says that at the end of 2017 ISIS forces held an 80-mile strip of the central Euphrates Valley. This matches the criteria's "mixed" case: most territory was lost, but a populated enclave of towns in the Euphrates valley was still held at year end.