AMSTERDAM — People had told Houssein throughout his life that there is nothing more beautiful than becoming a grandfather, but now when he sees a grandfather walking down the street with his grandchildren, he only feels aggrieved over his own loss. Houssein's grandchildren are among the hundreds of European children born in Iraq and Syria in areas formerly controlled by the Islamic State (IS). He has never seen them.

“What did they go through? Do they need medical care? Do they have enough food? These are questions that are constantly going through my mind,” Houssein, a Dutch citizen of Moroccan descent, told Al-Monitor. “My daughter might have made a barbaric decision by joining a terrorist organization, but her children did not have a choice. They were simply born in the wrong place.”

Houssein, who asked that his last name and place of residence be withheld for fear of reprisal by IS supporters, lost half of his family to the extremist organization. In early 2013, his daughter, Meryem, left the Netherlands to accompany her radicalized boyfriend to Syria. Houssein’s ex-wife kept in contact with her daughter, and Meryem eventually persuaded her to join them, in August 2014.

Houssein’s ex-wife took their son Ilyas, 14 at that time, with her. He was killed a few months after arriving in Syria, when coalition forces targeted an IS weapons depot in Tell Abyad, where Ilyas worked as a guard. Houssein lamented, “A grave to mourn, a last kiss on my son’s forehead, even an answer from his mother to the simple question why. IS took everything from me.”