Although the book is mostly a review of the last 100 to 150 years of scholarship on the subject of origins, Who Were the Early Israelites and Where Did They Come From offers a fine critique for the student or interested reader. The author, William Dever, is a professor of Near Eastern archaeology and anthropology at the University of Arizona, an institution noted for its on going work in the Middle East in collaboration with other institutions of higher learning, (including site work in Egypt under the directorship of Otto Schaden, with whom I studied Egyptian hieroglyphics years ago). With some thirty years of experience in the field, he is able to interlace his discussion of current theories with insights of his own taken from this perspective.
One of the points that I admire most about the book is the author's lack of rancor. Knowing as I do that the field of Biblical studies can present a minefield of controversy to anyone who professes any point of view, and that the journals can fairly smoke with comments and counter-comments to the editor, I find his openness laudable. The author does have his disagreements with the proponents of other theories, but he seems able to give them a fair and balanced airing and credit where credit is due. This isn't always easy in a field where contention rules, reputation is made by going against the current, and tenure may be given to those who successfully unseat their elders.
Part of the contention also arises from a peculiar need to justify the biblical narrative, to prove beyond a shadow of a doubt that it all "really happened" and is therefore "true." Like proving the existence of God, this is essentially a non-question. The religious reality of the Bible and its stories is a matter of faith; one either accepts it or doesn't according to ones own light. To the devout, proof is unnecessary as the author himself notes in his introductory chapters.
The modern political ramifications of Israelite origins is another embarrassing stone for the scholar to trip over, one of which Dever also makes note. The charge that Israelite origins or even the reality of its monarchal state was a fiction created to serve the political interests of their creators, and even more inflammatory, the possible suppression of "Palestinian history" by the modern state of Israel have made the issue of "historic reality" a major political problem that is not likely to go away anytime soon. With so much at stake both personally and nationally, any definitive statements in whatever direction are likely to be seen as an attack by someone.
With the above caveats, I tend to agree with Professor Dever's assessment of the situation. It seems highly probable that the later state of Israel arose from an indigenous source with small exogenous groups providing origin stories that were useful to later redactors to whose efforts we owe the modern version of the Biblical narrative. Whatever the motivation of these latter individuals, those of the earliest population or of the early monarchy were effected by conditions current during their own time. It is thus to these conditions and to this historical setting one must look to make sense of the record. Dever makes it quite clear from his discussion of the local infighting presented in the Armarna texts that conditions for the average citizen were deteriorating in the area during the Late Bronze/Early Iron age. Climate may or may not have been a factor in the Levant itself, but it most certainly had an effect on more northernly populations, since massive population movements occurred from there into the Near East. Change was almost unavoidable. With incursions of outsiders putting pressure on available land, increase in the number of lawless dissidents harassing the cities, quarrels between monarchs over control of their mutual boundaries, an unfair division of resources, the peasant population might well decide to cut its losses and run for it. It might also assume to develop an identity of its own irrespective of the ultimate origins of its constituent members.
In assessing the soundness of such a proposal, one might well benefit from the less emotionally charged example of the Anasazi origins and from research on the effects of climate on population movement and cultural change. To begin with, David Stuart's excellent account of the effects of climate change on the rise of the corn growing cultures of the four corners region of Arizona and surrounding states, makes a good parallel. In Anasazi America, the Professor suggests that the earliest inhabitants changed from a condition of transhumanescence to one of settled existence when climatic conditions made it necessary. With decline in resources, cultivation of multiple areas by people who considered themselves "kin" was a good way to spread risk widely. A need for organizing labor for water and land management probably led to a centralized authority, a class system of sorts, large scale architecture, in-group religious institutions, and an inequity in resource allocation. When climate changed again and the privileged elite were unable to manipulate conditions by their connections with nature or their management abilities, the sparsity of resources and inequity between classes became too pronounced for the culture to endure. The rural population disbursed. It had nothing to lose by doing so. Heading to the empty upland frontiers, they established architectural and technical hall marks suggestive of small family freeholds linked by obligations of shared risk, but the buildings and cultural menagerie did not arise from nothing; it arose as a derivative of what had been used in the area before.
The topics of climate and culture and climate and the rise and fall of polities are dealt with in very clear terms by Brian Fagan in The Long Summer, Harry Thurston in Secrets of the Sands and Richardson Gill in The Great Maya Draughts. In all four of the above books, there is ample data to support Professor Dever's thesis of an indigenous origin for the early Israelites.