A solid history of modern Thailand, running from the 1700s to the present day ~2009. Its also the only up-to-date socio-economic history of Thailand I could find on international bookshelves so this makes it somewhat of a reference text for the layman. The first third of the book is spent on pre-20th century Thailand -- sketching in particular the structure of its monarchy and the geopolitical region it dominated, the Mekong (stretching to Vietnam, Laos, Cambodia and Burma). The bulk, however, is spent on modern Thailand, with a brief chapter added in the second edition on the post-2006 era after which Thaksin was exiled, the military coup, yellow vs red shirt protests, etc.
The picture is drawn of a Thailand in which the urban-rural divide is strong not only in a geographic sense but also with respect to political identity; the monarchy is correctly perceived as a balancing force, but not because the monarchy was strong in itself. Rather, various regimes -- Thailand has a long history of coups and of power switching back and forth between the military and business, and traditionalists and reformers -- have tended to come back and reconfigure the monarchy as a figurehead standing for whatever it is they want it to stand for, as a means of aiding socio-political stability. As far as I can tell from the authors' narrative, the monarchy is a political construct. That said, the current king Bumipol -- rather old now -- has shown savvy in playing his at first largely ritualistic role lacking in executive power into a more symbolic one, cementing his status as above petty party politics. At the end of the day, however, that seems to be the problem -- Thailand has not seemed able to settle into a system where differences are worked through in parliament and under a constitution, as opposed to one where the armed forces (or whoever else) invariably feel the need to intervene, ostensibly in the name of nation and king but often with their own interests at heart.