The State Department was reportedly basing its limited genocide designation off a Holocaust Museum report "Our Generation Is Gone: The Islamic State's Targeting of Iraqi Minorities in Ninewa," or the Nineveh Plain in Northern Iraq. The museum led a fact-finding mission to Iraq in September of 2015 to investigate reports of genocide.
The mission never went to the actual Nineveh Plain, Shea said, but rather went to Iraqi Kurdistan and interviewed survivors of the ISIS onslaught. The report was quite "limited," Shea insisted, both in its "locale" and its "time frame." It only focused on ISIS activity on the Nineveh Plain in Northern Iraq between June and August of 2014.
As a result, while the report recognized atrocities committed against various ethnic and religious minorities, it only declared that the Yazidis around Mount Sinjar were victims of ISIS genocide.
"The self-proclaimed Islamic State (IS) perpetrated crimes against humanity, ethnic cleansing, and war crimes against Christian, Yezidi, Turkmen, Shabak, Sabaean-Mandaean, and Kaka'i people in Ninewa province between June and August 2014," the report stated.
"We believe IS has been and is perpetrating genocide against the Yezidi people," it added. "IS's stated intent and patterns of violence against Shia Shabak and Shia Turkmen also raise concerns about the commission and risk of genocide against these groups and requires further investigation."
Yet a growing consensus has emerged recognizing that genocide is being committed against Christians and other ethnic and religious minorities as well.
Both the European Union and the U.S. Commission on International Religious Freedom – a bipartisan federal commission that advises the State Department – have declared that genocide is taking place against these minorities.
Members of the International Association of Genocide Scholars signed an appeal to the U.S. Congress last fall saying that ISIS has committed genocide against Christians, Shi'a Muslims, Sunni Kurds, Yazidis, "and other religious groups."
Pope Francis said in July that "a form of genocide is taking place" in the Middle East against Christians. Presidential candidates including Democratic front-runner Hillary Clinton and Republicans Ted Cruz and Marco Rubio have also said that genocide is occurring.
Secretary of State John Kerry himself acknowledged it might be taking place in August of 2014. "ISIL's campaign of terror against the innocent, including Yezedi and Christian minorities, and its grotesque and targeted acts of violence bear all the warning signs and hallmarks of genocide," he stated.
However, Kerry was more guarded in a Feb. 24 exchange with Rep. Jeff Fortenberry (R-Neb.) at a House Appropriations Subcommittee on State and Foreign Operations hearing.
(Story continues below)
Subscribe to our daily newsletter
Pressed by Rep. Fortenberry to call the atrocities against Christians "genocide," Secretary Kerry stopped short of doing so, instead saying, "I share just a huge sense of revulsion over these acts, obviously. None of us have ever seen anything like it in our lifetimes."
"We are currently doing what I have to do, which is review very carefully the legal standards and precedents for whatever judgment is made," he added, noting that atrocities are occurring "not just in Syria, but in other places."
"There has been an increase, forced evacuation and displacement, which is equally disturbing, though it's not they are killing them in that case, but it's a removal and a cleansing, ethnically and religiously, which is deeply disturbing. So we are very much focused on this," he said.
Yet the evidence for genocide against Christians – apart from atrocities committed against other Middle Eastern religious minorities – is overwhelming, advocates say.
Firstly, "there's no evidence whatsoever of any Christian life left in the caliphate," Shea said – no active churches, liturgies, or congregations.
Aside from the many Christian clergy killed and taken hostage by ISIS, there have been many atrocities documented including the ISIS crucifixion of 12 Christian missionaries in Syria, the kidnapping of 180 Assyrian Christians and the execution of three of them in Hasakah, and the beheading of 21 Coptic Christians on a Libyan beach in February of 2015.