A 34-year-old man from Houston who sent a résumé and cover letter seeking a job inside the Islamic State was captured alive on the battlefield alongside another American fighting for the terrorist group, according to the Syrian Democratic Forces, who announced the arrest on Sunday.
The two Americans reported captured, Warren Christopher Clark and Zaid Abed al-Hamid, were seized alongside other foreign fighters, including citizens of Ireland and Pakistan. They were taken during an operation targeting the Islamic State’s last pocket of control in northern Syria, according to a statement issued by the Syrian Democratic Forces, the Kurdish-led and American-supported militia that is fighting to take back territory from ISIS.
Only four other Americans are known to have been captured alive on the battlefield in Iraq and Syria, according to a database maintained by George Washington University’s Program on Extremism. Similarly small is the number of Americans who have returned to the United States after joining the terrorist group.
Extraditions to the United States of Mr. Clark and Mr. al-Hamid, whose surname was also spelled al-Hamed, would make them only the 15th and 16th American adults to return from joining ISIS in Iraq and Syria.
“The number is minuscule,” said Seamus Hughes, the deputy director of the program at George Washington. “To put it in context, the Brits are talking about hundreds of returnees.”
Among the documents left behind in a house that had been occupied by ISIS in Mosul, Iraq, were Mr. Clark’s résumé and a cover letter, which begins: “Dear Director, I am looking to get a position teaching English to students in the Islamic State.”
“I believe that a successful teacher can understand a student’s strengths and weaknesses,” it continues, “and is able to use that understanding to help students build on their understanding of the English language.”
The letter and accompanying résumé, which were authenticated by Mr. Hughes, point to the recruit’s naïveté and underscore that he was drawn to the Islamic State’s promise of building a Muslim-only state.
His résumé indicates that he received a bachelor’s degree from the University of Houston and that he served as a substitute teacher in the Fort Bend Independent School District in Sugar Land, Tex., for more than two years. He later moved to Saudi Arabia to teach English and then taught English for three months in Turkey. His résumé ends in June 2015, indicating that he probably joined ISIS after that.
Little is known about the American said to be captured alongside Mr. Clark, beyond his age, 35. The Syrian Democratic Forces did not release where he is from in the United States.
A similarly spelled name — Zaid Abdul-Hamid — appears in a cache of ISIS registration forms indicating that he provided a reference for a recruit from Trinidad and Tobago when that recruit joined the group in 2014. The same form indicates that Mr. Abdul-Hamid was in Raqqa, Syria, at the time that he acted as the reference.
Col. Scott Rawlinson, a spokesman for the American-led military coalition in Baghdad, said in an email that the coalition was “aware of open source reports of reportedly American citizens currently in custody believed to be fighting for ISIS.”
“However, we are unable to confirm this information at this time,” he added. “The incident is under investigation.”
Last month, President Trump’s announcement that the United States would withdraw its forces stationed in Syria prompted the resignation of his defense secretary and accelerated the resignation of the White House’s senior envoy to the fight against ISIS. Both Defense Secretary Jim Mattis and the senior presidential envoy, Brett McGurk, said that the unexpected withdrawal amounted to abandoning America’s allies in the region, especially the Syrian Democratic Forces.
In recent days, White House officials have softened Mr. Trump’s stance, saying that the withdrawal will not happen right away and that it will be carried out in a coordinated manner. On Sunday, the president’s national security adviser, John Bolton, appeared to reverse course, telling reporters in Jerusalem that the pullout was conditional on defeating the last remnants of ISIS and on Turkey’s ensuring the safety of America’s Kurdish allies.
According to three separate reports, including an assessment by the Pentagon’s inspector general, ISIS still maintains a force of 20,000 to 30,000 members in Iraq and Syria.
The last time the group was declared defeated in 2010, the C.I.A. estimated that it was down to just 700 fighters.