According to UNSC 1373(2001), States should bring alleged terrorists to justice, reflecting the seriousness of the crimes they have committed, which forms a vital aspect of an effective counterterrorism strategy. Consequently, States need to ensure that any person who participates in the financing, planning, preparation, or perpetration of terrorist acts or in supporting terrorist acts is brought to justice. States must similarly ensure that such terrorist acts are established as serious criminal offences under domestic law and that the punishment duly reflects the seriousness of such terrorist acts.

When committed during armed conflict, some terrorist acts can constitute war crimes, and where terrorist acts are conducted as part of a widespread or systematic attack directed against a civilian population, they can constitute crimes against humanity. In some situations, terrorist acts may also constitute genocide if they are committed with intent to destroy, in whole or in part, a national, ethnic, racial, or religious group.

This report provides a short overview of the status quo concerning Indonesian foreign terrorist fighters and the approach taken thus on prosecuting those that have returned. After discussing some of the legal, institutional, and evidentiary challenges, this report provides an overview of the opportunities for Indonesia to adopt cumulative charging for terrorist offences and core international crimes.