Appeal of Islamic State’s ideology raises questions about totality of its defeat, even as group loses its territory and less committed members fall away.

The baby was born during the death throes of Islamic State’s caliphate—when all that remained of its once vast domain was a cluster of tents in a remote corner of Syria. And yet far from renouncing the group and its ideology, the infant’s mother vowed he would grow up to fight for Islamic State when it rises again. “I will raise him according to the way of Islamic State,” said Umm Abdulrahman, 27 years old, breast-feeding the child beneath the black fabric covering everything but her eyes outside the village of Baghouz. “Despite everything—the hunger and bombardment—we felt at ease.” She is one of thousands of women to emerge from this last sliver of territory held by Islamic State, many unrepentant over the group’s atrocities and bent on passing its brutal brand of extremism on to the next generation. Few ever doubted that a U.S.-led coalition of 79 countries would ultimately prevail militarily over Islamic State. But the enduring appeal of the militants’ ideology among people like Umm Abdulrahman raises questions about the totality of its defeat.

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