Disputes over water constitute a major area of disagreement between Israel and Palestine. The uncoordinated and irresponsible environmental actions on both sides have created serious ecological and humanitarian hazards that require rapid, yet sustainable action. Those who argue that the water problem can be resolved only as part of a comprehensive peace deal between the Israelis and Palestinians fail to recognise both the urgency and the potential of cross-border water cooperation. The bottom line of this Flanking Cooperative Idea is that because water- and sanitation-related issues extend both horizontally across national borders and vertically across various sectors, environmental cooperation can be used to create positive linkages with and spill-overs into other policy fields with the potential to initiate new forms of collaboration in currently deadlocked areas, including the field of disarmament and non-proliferation.