A pretty good, even provocative book.
Muslih describes the Palestinian political framework as one composed of competing families that established themselves in Palestine throughout the successive waves of imperial conquer. The vast majority of these families traced their origins to the outside of Palestine (most to Southern Arabia and Yemen) and this is not an accidental argument, as some of them transported intra-tribal conflicts from their native homeland to Palestine, and still engaged in these conflicts some 1200 years after their settlement in the region.
By the end of the 19th century, these families had to deal with the emerging threat of Jewish colonists moved by an explicitly political ideology - Zionism. However, these families overwhelmingly associated themselves with the continuity of Ottoman power to ensure their control of the region, and mostly identified with the Pan-Islamist principles of the Ottoman - no wonder the few vocal voices of the nascent Arab nationalism were Christians.
With the growth of Turkish chauvinism among the Ottomans and their ultimate collapse, the Arab political dynasties had no option but to adopt Arab nationalism as a mode of political survival. Inside Palestine, different groups of Arab nationalists had different priorities, with some - mostly young politicians from families outside of traditional power - preferring their union with Syria and others - mostly older politicians determined to protect their power structures and moved by an abstract sense of nationalism - petitioning for independence.
What both groups were unanimous were in their opposition to Zionism, though. Although most settlers bought their land from rich absentee landowners or from the Ottoman empire directly, public discourse fanned the flames by arguing settlers were dispossessing poor peasants and taking their lands. This opposition was further crystallized by Zionism's open objective of creating a Jewish independent homeland in Palestine and in the lack of respect of Jewish settlers for customary rural and property law. It is, of course, also of the nature of Arab nationalism - and to be fair with the Arabs, most of post-Ottoman nationalism - to be extremely chauvinist and arabising. Muslih mentions en passant the massacre of Armenian migrant workers in Aleppo motivated by this Arab nationalism, which would reach its apotheosis in the many massacres and ethnic cleansings of the 20th century.
However, the idea that a Jewish homeland had an inherent right to be established in the region can only be seen, in retrospect, as a massive act of idealism. No nation in the world ever gave up land which is considered legally theirs in benefit of an abstract claim, and to consider that the Arabs had a moral obligation to do so only because another country told them so is plainly absurd. In a very cynical way, the Zionists acted as one more of the many foreign armies that passed through their land, clashing with the last, established power. Arabs and Jews fought, the Arabs lost. Had this happened in 1850 and not in 1948, it probably wouldn't have raised any eyebrows.