Internal displacement in Sri Lanka exists in the context of a protracted condition of insecurity produced by intractable war and polarization of society along ethno-political lines. People remain exposed to risks and threats to their security over prolonged periods of time and the mobilization of inter- and intra-ethnic tensions exacerbates the breakdown of trust and protection at community level. Humanitarian agencies seeking to assist displaced civilians are compelled to grapple with challenges about how to engage in the most skilful and effective way in a risky and difficult environment. Drawing on field interviews in Trincomalee District, the article examines humanitarian agency approaches to protection in this politically challenging context. It is divided into six sections - international policy discussion on protracted internal displacement situations; the intractability of war in Sri Lanka; humanitarian approaches to protection; the political contours of the conflict in Trincomalee; the specific protection challenges confronting humanitarian agencies as they work in this highly politicized and militarized arena; and finally, the lessons and creative strategies crafted by agencies to negotiate these challenges.