'The Tories', as you may have gathered from the title, is a book which focuses on the Nation-State, but this requires a short explanation - Clark's conception of this notion focused very much around the nation's accumulated prestige, it's self-confidence, it's position in the world, and it's basic internal cohesiveness and economic strength. Clark links the continuing decline of those factors in Britain over the period in question with the individual personalities in the Tory Party - and how individual ambition in particular always takes precedence over the national interest. This is a frank assessment on Clark's part of the country and the Tory party, both of which he so clearly loved; of how both allowed themselves to drift aimlessly at points; and Clark's quiet anger at short-term thinking, of the 'management of decline' mindset.
Clark combines certain themes in each section - the misjudgements in the foreign policy of the thirties to the leaderships of Stanley Baldwin and Neville Chamberlain, and their opposition in the shape of Churchill - to excellent effect. You may disagree with (for example) Clark's purely realpolitik arguments that any focus on central Europe in the thirties was utterly contrary to Britain's national interests; (which, indeed it was, purely on those terms, as Clark amply demonstrates) that Chamberlain's essential failing was to not provide an alternative, 'imperial'/Mediterranean vision as a counterpoint; and that the real problem with appeasement was that it ever got itself entangled in central Europe in the first place, but they are arguments which are highly persuasive on their own terms. (Despite Clark characteristically weighting some events, such as the Hess flight, too highly)
This book was meant to be Clark's magnum opus, although I get the sense that it rather fell down with the book world on two accounts; it was too truthful, and much too fun. This is not an academic book; it is a political/historical polemic, well upheld by personal experience and a regard for pinning down historical personalities and political trends. But it is never, ever, a dull book.