In a commentary, Cameron Sumpter, a research fellow with the Centre of Excellence for National Security (CENS), and Chaula Rininta Anindya, a research fellow at NTU’s RSIS, said that repatriating and reintegrating citizens who travelled to the Middle East to join ISIS is uncertain, expensive and politically unpopular. But leaving them in hazardous refugee camps with thousands of likeminded militants may pose even greater long-term problems.