What contribution can diplomats and technical experts make to support transboundary water cooperation? And how can such cooperation be leveraged to facilitate wider-ranging regional integration? To respond to these questions, adelphi convened a group of experts whose discussions have resulted in a report on how to strengthen foreign policy for transboundary waters. This report calls on foreign policy makers to exert stronger political leadership in water diplomacy and to actively accompany and facilitate the efforts of technical and development experts. It shows that encouraging greater cooperation over transboundary waters offers significant prospects for the resolution of political conflicts and greater regional integration. To this end, this report argues that foreign policy makers should ensure stronger agency at the international level, realize potential synergies between political and technical engagement, and build the necessary capacity at the national, basin and global levels. To manage the coming challenges, driven in part by climate change, foreign policy makers must drive an internationally coordinated, cross-sectoral engagement.