With "A Good Man in Africa," William Boyd made a precocious debut. Though somewhat derivative of Evelyn Waugh and Kingsley Amis, this story of a British diplomat's hapless adventures in Africa was told with brio and generous helpings of black humor, and it marked the start of a promising career. Now, only a year later, Mr. Boyd has more than fulfilled the bright promise of the first novel. "An Ice-Cream War" is more ambitious in scope and theme than "Good Man," and it represents Mr. Boyd's discovery of his own voice—an elastic voice that is capable not only of some very funny satire but also of seriousness and compassion.

Played out against the backdrop of World War I, "An Ice-Cream War" examines the consequences of that conflict, which would so fundamentally change the British state of mind. The setting is marginal as far as the main theatre...