Following the Israeli Declaration of Independence, Magnes ceased advocating binationalism, and accepted the existence of the state of Israel, telling one of his sons "do you think that in my heart I am not glad too that there is a state? I just did not think it was to be." On May 15, 1948, following the declaration of independence, he called Israeli President Chaim Weizmann to express congratulations. During the 1948 Arab-Israeli War, Magnes lobbied for an armistice, and proposed a plan for a federation between Israel and a Palestinian state which he called the "United States of Palestine", under which the two states would be independent, but operate joint foreign and defense policies, with Jerusalem as the shared capital. He spoke with American, Israeli, and Arab officials, who expressed some interest in his plans. During the summer of 1948, he also began to lobby increasingly for a solution to the Palestinian refugee problem.