Researchers at Oregon state University say they have found evidence to the contrary, showing that the world’s 263 trans-boundary rivers (whose basins cover nearly half the land surface of the world) generate more co-operation than conflict. Over the past half-century, 400 treaties had been concluded over the use of rivers. Of the 37 incidents that involved violence, 30 occurred in the dry and bitterly contested region formed by Israel and its neighbors, where the upper end of the Jordan river was hotly disputed, and skirmished over, before Israel took control in the 1967 war. And some inter-state water treaties are very robust. The Indus river pact between India and Pakistan survived two wars and the deep crisis of 2002.