This is a concise history of modern Libya, with token background from the Ottoman period, slightly more detail from the Italian colonial period, and the vast majority of its focus on the monarchy (1951-1969) and the Qadhafi period (1969 to present). The author deals almost exclusively with political and economic history, with very little attention to cultural or religious themes.
Even on such limited terms, the book fails in a number of ways. First, Vandewalle has an odd habit of not defining terms that a reader of such a general history might find useful. For example, he refers often to the Sublime Porte -- a term that a general student of the Middle East and especially of the Ottoman Empire ought to know, certainly, but probably not familiar to the general reader. Another example is the Bab al-Aziziyya, which the author defines on page 150, but which he began using on page 121 (without any hint that a definition was forthcoming).
Second, and more importantly, the book lacks a surprising amount of detail. We are informed that a small group accomplished a coup against King Idris in September, 1969, but we are told almost nothing else: where did the coup happen? How did it happen? Perhaps a palace was stormed, or military installations seized? We are not even told of the fate of King Idris -- was he executed, banished, imprisoned, or left alone? These are all natural questions when dealing with something as momentous as the coup that changed Libya from a shaky kingdom to a radical, terrorist-sponsoring anti-state.
We are informed that two Libyan planes were shot down over the Gulf of Sirt after some kind of dispute. What was the nature of the dispute? Again, we are not told. And very frequently, as with the Gulf of Sirt incident and the Lockerbie bombing, Vandewalle makes allusion to the matter long before offering what scant detail he does provide, meaning the reader must already have some basic background or be left with no means of evaluating the validity of the author's interpretation.
As to that last point, another clear weakness of the book is that the footnotes are extremely sparse. Generalization is far more forgivable where the author directs the conscientious student to further information. That said, this book is a slim 206 pages of text -- the author easily could have added more helpful material without making the book unwieldly.
One final, important weakness is that the author frequently jumps around chronologically, resulting in a confused narrative. Again, the author assumes too much familiarity on the part of the reader, which familiarity makes little sense given the scope of the book.
EDIT: I recommend Libya: From Colony to Independence, by Ronald Bruce St. John, for readers interested in the subject.