In the eastern Mediterranean Sea lies what may be one of the world's biggest natural gas fields. Two of them, Tamar and Leviathan, have already been licensed by Israel to Israeli and foreign investors. The potential economic bonanza raises the question of which countries are entitled to share in the windfall and how it will be apportioned between them.RELATED:The Israeli judiciary: A model of independence (Premium)Can Israel's democracy be saved? (Premium)Been there, done that (Premium)The right to democratic "McCarthyism"(Premium)Israel's needs an urgent education reform (Premium)International law stipulates that every state is entitled to exploit the natural resources of the seabed, including oil and gas fields, up to 200 nautical miles from its coast. Where the distance between two opposite states is less than 400 nautical miles, the two states must agree on a median line between them. The distance between Cyprus and Israel is approximately 260 nautical miles. An as yet unpublished agreement was signed by the two countries delimiting a median line between them. This line allows each state to exploit the natural resources of the seabed up to a distance of approximately 130 miles from its coast. The gas fields of Tamar and Leviathan are well within this 130 mile zone. Turkey has raised vociferous objection to the Israel-Cyprus agreement based on the country’s interest in ensuring that the Turkish republic of Northern Cyprus also benefit from some of the income generated by gas fields, even though the region is adjacent to the coast of the (Southern Greek-speaking) Republic of Cyprus. The other legal issue is delimiting the line between adjacent states; in this case Israel and Lebanon. The rule is that the maritime line commences where the land boundary meets the sea - i.e. Rosh Hanikra - and extends into the sea on a line drawn to connect points that are equidistant from the two coasts. In order to ensure an equitably drawn maritime line, the particular geographical features of the coasts such as headlands and bays must be taken into account. Since no two coast lines are identical, the delimitation of such a maritime boundary requires agreement between the two states. While the two gas fields Tamar and Leviathan are well on the Israel side of any possible Israel-Lebanon maritime boundary, it is possible that future fields may straddle such a line. For this reason, it is imperative that Lebanon and Israel define a boundary but so far Lebanon has shown no willingness to enter into negotiations. Lebanon has a vital interest in exploiting gas and oil fields opposite its coast, and therefore it is safe to assume that it will want to reach an agreement on a maritime boundary either explicitly or by acquiescence. Furthermore, investment and exploitation of gas and oil fields is obviously conditional upon being able to offer investors a secure and stable environment. On Israel's Southern coast, Egypt has also reached an agreement with Cyprus delimiting a common maritime boundary and Egypt unilaterally marked its maritime boundary with the Gaza strip. Israel has likewise unilaterally defined a maritime boundary with the Strip, thus in the future the Gaza strip will also have a wedge-shaped section of seabed to which it is entitled. In the Gulf of Eilat, Israel has signed an agreement delimiting its maritime boundary with Jordan and has an unwritten understanding with Egypt as to the border. However, it is unlikely that there are exploitable gas or oil resources in the Gulf. Despite recent Lebanese bellicose statements, there is the possibility that the business-orientated state will not wish to undermine its future economic development, meaning that a mutually agreed delimitation of the maritime boundary could be in the pipeline.Thewriter teaches international law at the Hebrew University and is theformer legal adviser to the Ministry of Foreign Affairs.