Of course, it might benefit the Jews.
From the New York Times Magazine, October 19, 1958, by Eric Johnston, who was a US envoy to the Middle East during the Eisenhower administration (reproduced here):
Between 1953 and 1955, at the request of President Eisenhower, I undertook to negotiate with these States a comprehensive Jordan Valley development plan that would have provided for the irrigation of some 225,000 acres. This is an area comparable in size and in climate to the Salt River irrigation project near Phoenix, Ariz., which produces crops valued at $326 per acre a year. After two years of discussion, technical experts of Israel, Jordan, Lebanon and Syria agreed upon every important detail of a unified Jordan plan.
But in October 1955, it was rejected for political reasons at a meeting of the Arab League.Syria objected to the project because it would benefit Israel as well as the Arab countries.Three years have passed and no agreement has yet been reached on developing the Jordan. Every year a billion cubic metres of precious water still roll down the ancient stream, wasted, to the Dead Sea.