Israel has met with surprise and concern the announcement that Jordan will not renewthe lease over two areas of land currently administered by Israel. The response from the Israeli Agriculture Minister, Uri Ariel, was especially strong, he threatened that Israel could cut its delivery of water to Jordan from four days to two. Since the signing of the 1994 peace treaty, water co-operation between the two countries has been consistently robust, with Israel providing Jordan with greater quantities of water than originally stipulated in the treaty. Comment Jordan is one of the most water scarce countries in the world and any reduction in water supplies would be a blow to the country.  Jordan’s water scarcity problem is being exacerbated by an increasingly warm and dry climate, in what is already one of the most arid parts of the world. Jordan is almost landlocked, making it difficult to use an Israeli-style system of desalination to alleviate pressure on water supplies. Three other factors also add to Jordan’s precarious water situation: it lies downstream from the Yarmouk-Jordan River system, making it vulnerable to upstream interference from Israel or Syria. Moreover, Jordan’s groundwater is diminishing at an alarming rate; it extracts 200 per cent more from its aquifers than is sustainable. A newly developed aquifer that feeds Amman is expected to be exhausted in the medium-term. Finally, a rapid increase in population, caused by refugees fleeing the conflict in Syria, also puts pressure on scarce water supplies in Jordan. In some parts of the country, the influx of refugees has almost doubled the demand for water. While Jordan’s water resources are significantly threatened, there is scope for transboundary co-operation with other riparians, especially Israel. Although their diplomatic relations have not always been warm, co-operation over water has been remarkably productive over the last two decades. The Israel-Jordan Joint Water Committee meets regularly and water management was one of several priorities in the 1994 peace treaty between the two states. It is fairly clear why Jordan would seek close co-operation with Israel over water; it has very little, while Israel has geographic and political advantages that give  it greater control of the Jordan River Basin. For Israel, there are equally compelling, if less obvious, reasons to co-operate with Jordan over water and other resources. Israel shares its longest, and arguably most stable, border with Jordan. Israel is also conscious that water shortages may lead to the type of destabilising unrest seen in other parts of the region this decade. Jordan is considered an important strategic ally and its security is an important buffer for Israel’s own security. Jordan’s decision to end the land lease comes at a particularly perilous time for the country. A series of protests, targeting economic reforms, unnerved the country’s leaders earlier this year and ultimately led to the dismissal of Hani Mulki from his position as Prime Minister. Despite popular opposition to tax increases, Jordan’s economy may struggle without them, due to spiralling public debt and a lack of investment caused, in part, by regional conflict. Public sentiment has also hardened against the Jordan-Israel land deal. A week before King Abdullah announced that the lease would not be renewed, 85 parliamentarians petitioned him to intervene against the land deal. Jordan now has a chance to benefit, regardless of whether the lease is renewed or not. If the lease is not renewed, popular discontent may be dampened enough to allow unpopular economic reforms to continue. On the other hand, if Jordan chooses to negotiate with Israel instead, the land may serve as a useful bargaining tool to extract greater concessions or co-operation over increasingly scarce river resources.