US forces' withdrawal from northern Syria could negatively impact Christian communities living in the predominantly Kurdish region, Thomas Schmidinger, who wrote the book Rojava, wrote in The Region.
Armenians and Assyrians who live in border towns like Qamishli may be forced to flee if Turkey steps up its military operations into the region following the US exit.
The United States will abandon recently built observation posts on the Turkish-Syrian border, aimed in part at defusing tensions between Turkey and Syrian Kurdish rebels.
Qamishli was founded after World War I by Christians and Jews who preferred French-protectorate Syria over Turkey.
"Until the 1970s, the city had more than 60 percent Christians, and they still are an essential part of the diversity of this multi-ethnic and multi-religious town," he added.
Armenian communities are also found in Ras al-Ayn, al-Hasaka, and Al-Malikiyah. Some towns have Armenian schools where their native language -- Western Armenian, which differs from what is used in the Republic of Armenia -- is taught alongside Arabic.
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Many Armenians there still view Turkey as perpetrators of the genocide against their ancestors. Many migrated to in the area after massacres. "Family histories are told in detail," Schmidinger said.
Under the structures of the self-administration, which were set up in 2012, religious freedom is granted," Schmidinger wrote.
"There are even Christian churches of Kurdish converts in the region. ... If Turkey continues to invade the remainder of the Kurdish region, these Christians will have to flee again."
He added that "all of these Armenians are descendants of survivors of the 1915 Genocide. When talking to Armenians in Qamishli and Dêrik, I realised several times how this history is still present. For the Armenians in the region, Turkey is still predominantly seen as the nation who massacred their fathers, mothers, grandfathers and grandmothers. Although some of the older Armenians in the area still speak Turkish as a second or third language, they fear Turkey as the nation of perpetrators who never even accepted their historical responsibility for the Genocide. Family histories are told in detail. Every church has a memorial for the victims of the Genocide, and every year in every community the 24th of April is celebrated as Armenian Genocide Victims Remembrance Day."