As early as April 1948 the newly independent nation of Israel put into effect Plan Dalet, which called for the expulsion of Palestinian Arabs from areas allotted to the Palestinians under the United Nations (UN) partition plan. The combined forces of several Arab nations and Palestinian guerrillas attacked the Israelis. Israel defeated the Arab forces between 1948 and 1949, taking much of the land that had been granted to the Palestinians by the UN in 1947. Unresolved territorial and refugee issues led to further Arab-Israeli wars.