The author recalls those occasions in European history when states had to choose whether to wage war on land, or on the sea, and latterly in the air as well. He describes the results of their decisions about allocating defence resources and considers whether a different mix of land, sea and air forces might have produced different results. This survey of defence strategy starts in 490 BC with the Persian invasion of Greece and ends with some remarks about strategic choices after the Cold War.

As the road to hell is paved with good intentions, so the path to defense organization is well carpeted with good advice. The wise men tell us that advice, good or bad, is never welcome, so the writer who is rash enough to add to the existing pile of books on this subject in the United States and, to a lesser extent in the United Kingdom, must have a good excuse. This book offers two.