separately. Causes of the first wave, December 1947 – March 1948 Morris gives no numbers regarding the first wave, but says "the spiral of violence precipitated flight by the middle and upper classes of the big towns, especially Haifa, Jaffa and Jerusalem, and their satellite rural communities. It also prompted the piecemeal, but almost complete, evacuation of the Arab rural population from what was to be the heartland of the Jewish State—the Coastal Plain between Tel Aviv and Hadera—and a small-scale partial evacuation of other rural areas hit by hostilities and containing large Jewish concentrations, namely the Jezreel and Jordan valleys." More specific to the causes Morris states: "The Arab evacuees from the towns and villages left largely because of Jewish ... attacks or fear of impending attack, and from a sense of vulnerability." According to Morris expulsions were "almost insignificant" and "many more left as a result of orders or advice from Arab military commanders and officials" to safer areas within the country. The Palestinian leadership struggled against the exodus. Causes of the second wave, April–June 1948 According to Morris the "Haganah and IZL offensives in Haifa, Jaffa and eastern and western Galilee precipitated a mass exodus." "Undoubtedly ... the most important single factor in the exodus of April–June was Jewish attack. This is demonstrated clearly by the fact that each exodus occurred during or in the immediate wake of military assault. No town was abandoned by the bulk of its population before the main Haganah/IZL assault." Also many villages were abandoned during attacks, but others were evacuated because the inhabitants feared they would be next. A major factor in the exodus was the undermining of Palestinian morale due to the earlier fall and exodus from other towns and villages. Morris says that the "Palestinian leaders and commanders struggled against [the exodus]" but in many cases encouraged evacuation of women children and old people out of harms way and in some cases ordered villages to evacuate. Regarding expulsions (Morris defines expulsions as "when a Haganah/IDF/IZL/LHI unit entered or conquered a town or village and then ordered its inhabitants to leave") Morris says that the Yishuv leaders "were reluctant to openly order or endorse expulsions" in towns but "Haganah commanders exercised greater independence and forcefulness in the countryside": "In general Haganah operational orders for attacks on towns did not call for the expulsion or eviction of the civilian population. But