 In 1961 Khalidi also said that the Zionists had military superiority and that Plan Dalet, the Zionists' military plan executed in April and May 1948, aimed at expelling the Palestinians.In his work dedicated to the topic, "A Historical Survey of Proposals to Transfer Arabs from Palestine 1895 - 1947", Rabbi Dr. Chaim Simons provided examples of the writings and recorded words of important Zionist leaders including Theodore Herzl, David Ben-Gurion, Chaim Weizmann, Vladimir Jabotinsky, Baron Edmund de Rothschild and Moshe Shertok, demonstrating that the concept of 'transfer' was present from the earliest days of Zionism, that it was viewed as being a crucial action, and concludes that 'transfer' was in fact Zionist policy.Simons concludes further that the Zionist leadership has no viable alternative.