The Donald Trump administration’s decision Sunday to allow a Turkish incursion into northeast Syria threatens to let loose thousands of Islamic State prisoners onto the battlefield from jails that have become a hotbed of militant ideology, US officials warn.

In the wake of a surprise decision to remove more than 100 American troops from the safe zone, the White House said Sunday that European nations such as France and Germany had refused to take back IS fighters.

The foreign militants potentially displaced by the retreat of the Kurdish-dominated Syrian Democratic Forces will now shift into Turkey’s custody, White House press secretary Stephanie Grisham said after a Sunday call between Trump and Turkish President Recep Tayyip Erdogan.

But Trump’s position does not appear aligned with the rest of the administration, blindsided by Sunday’s move. The Pentagon has feared for months that a Turkish incursion would stretch the Syrian Democratic Forces, or SDF, preoccupied with administering overcrowded camps hosting the families and children of IS fighters at facilities such as al-Hol in northeastern Syria, where fewer than 500 Kurdish guards tend to nearly 60,000 prisoners.