The Italian national project is a potent but erratic force, argues historian Duggan (A Concise History of Italy) in this thoughtful history of Italian politics from the Napoleonic Wars that jump-started the nationalist movement to the present-day rise of secessionist parties that want to bury it. The romantic patriots of the 19th-century risorgimento, Duggan contends, faced daunting challenges in unifying their homeland: a peninsula fractured into squabbling statelets speaking mutually incomprehensible dialects; citizens whose civic allegiance extended no further than the local church tower or mafia boss; Northern Italians' contempt for the corrupt and backward South; a militantly antinationalist Catholic Church. Making a virtue of necessity, he contends, patriots made nation building into a quasireligious moral reclamation that they hoped would infuse order, discipline and martial vigor into the allegedly degenerate Italian character, a vision that inspired liberal democrats but culminated in Mussolini's Fascist dictatorship (of which the author offers an especially insightful account). Duggan's lucid, wide-ranging but conceptually focused narrative examines the tension between exaggerated aspirations for a united Italy—in literature, art and opera, as well as political ideology—and the often disappointing, fractious reality. The result is an illuminating study not just of one nation but of nationalism itself. Photos. (Apr. 28)