The response to terrorism also requires a preventive approach. Leaving tens of thousands of people to languish in camps in Syria is deeply shortsighted. The conditions in the camps provide the ideal environment for the nurturing of further extremism and hatred. The lessons from Camp Bucca, the American-run detention facility in Iraq where the Islamic State’s founder, Abu Bakr al-Baghdadi, was schooled, are clear — grievance and radicalization only deepen the longer people spend there.

Moreover, it should be clear that tarring the children in the camps with the same brush as hardened Islamic State fighters is not right: Born of rape, into detention, indoctrinated into the Islamic State’s cult of cruelty, these children have had little or no agency over their predicament. The situation in Al-Hol camp in Syria is particularly dire: Just getting to the camp, or soon after arrival from late 2018 onward, hundreds of children died from pneumonia, dehydration and malnutrition. Infants — some with shrapnel injuries — are acutely malnourished and many have limited or no access to medical care. These children desperately need care, not further victimization.

Governments should immediately take back their citizens in these camps who are most vulnerable: unaccompanied children and orphans; pregnant girls; persons with disabilities; and children with mothers with no record of violence, taking into account the best interests of the child. Many have been subject to abuses, including sexual violence, and they should be provided with appropriate assistance as well as support with reintegration.

Governments should also allow for the immediate return of terrorist suspects in cases where there is enough evidence to prosecute them in their national courts with fair trial protections without resorting to the death penalty. Where evidence is difficult to obtain, governments should explore if lesser crimes can be prosecuted to allow for some accountability. Risk and, where in doubt, nationality assessments should be undertaken for the remaining categories. Governments should adopt tailor-made security measures depending on the individuals, with a view to a progressive repatriation of all concerned and effective reintegration programs for returnees.

This isn’t utopian thinking. A number of governments have been more forward-thinking: Kazakhstan and Kosovo, for example, have taken back hundreds of women and children, and some men. Other countries, including Belgium, France, Germany, Ireland, Italy, Tunisia and Britain have accepted back individual children, sometimes with their mothers. But this is simply not enough.