The obligations under international law of the foreign fighter’s state of nationality or habitual residence, state of transit and state of destination

Abstract

The phenomenon of foreign fighters raises a series of issues under international law for their State of origin (i.e. their State of nationality or habitual residence), the States of transit, and the State of destination (i.e. the State where the armed conflict takes place) at all stages of their mobilization, i.e. before joining an armed conflict, during the armed conflict, and upon their return. First, the question arises whether and to what extent States of origin and States of transit have an obligation under international law to prevent the departure of foreign fighters, including in light of relevant Security Council Resolutions. Moreover, due to the linkages between foreign fighting and terrorism, many States may, and are indeed, using their national anti-terrorism legislation to prevent the departure of foreign fighters. Second, against the background of the current foreign fighters mobilization, some States have taken measures to prevent foreign fighters from returning, namely by revocations of citizenship or exclusion orders. The implications under international law of such measures will be assessed as well. The influx of foreign fighters finally also raises the question what the obligations are of the State of destination, not only to prevent the foreign fighters from arriving, but also as regards the treatment of foreign fighters during an armed conflict.