This report is based on a series of interviews with US officials and details two efforts to achieve US objectives to take back territory from ISIS in Syria—with elements trained in Turkey, as part of the Train and Equip program, and through the Syrian Democratic Forces (SDF), the dominant local force in northeastern Syria.

The Train and Equip program failed to meet its objectives, while the SDF has been a tactical success. The military successes, however, have created broader political problems with Turkey, a US treaty ally, and a key external actor in northern Syria. The different outcomes make these two programs worth studying in depth.