Returning Isis fighters

A chara, – Your editorial on the apparent downfall of Isis says that "the thousands of foreign fighters returning to Europe and elsewhere will continue to pose a threat for the foreseeable future" (October 16th). It goes on to say, "European governments must prepare for that". Forgive me for stating what should be glaringly obvious, but isn't the best way of preparing for the threat that these fighters would pose be to take steps to ensure that they are never allowed to return? – Is mise,

Rev PATRICK G BURKE,

Castlecomer,

Co Kilkenny.