Sir John Keegan, the world's foremost living military historian, has written a book which thoroughly examines the role of intelligence in warfare, reaching a conclusion that is sure to tick off the intelligence community: even the best military intelligence on an enemy's forces and plans is secondary to having adequate military forces and planning with which to defeat the enemy. Keegan gives a number of case studies, including the World War II submarine Battle of the Atlantic, Stonewall Jackson's 1862 Shenandoah Valley campaign, Admiral Nelson's hunt for the French fleet in the Mediterranean, and the battle of Crete, to show the effect of various degrees of knowledge of the enemy's forces and plans on the outcome of battle. The battle of Crete contributes most to Keegan's conclusion on the usefulness of military intelligence: the commander had a high degree of knowledge of German forces and plans for the batttle, so much so that when the first German paratroopers began to land while he was eating breakfast, he looked up and said: "they're on time." Yet the British lost this battle despite this high degree of foreknowledge of the German invasion plans. Keegan would not deny the importance of military intelligence in future military operations. With the satellite intelligence and codebreaking available today, much can be learned about enemy forces. However despite this foreknowledge, the intention of the potential enemy's command structure can still be unknown: witness the beginning of the first Iraq War, when Iraqi forces were massing on the Kuwait border, yet U.S. intelligence did not believe Saddam would cross the border and invade Kuwait. Technological intelligence capabilities have been overemphasized by the U.S. intelligence community since Carter's Stansfield Turner headed the CIA, to the detriment of even more valuable human intelligence. Keegan's book, as all his books, reaches a reasoned balance: good intelligence is vital, but ultimately the outcome of military conflicts is determined by the skillful deployment of superior military forces--superior not necessarily in numbers, but in training, tactics, weaponry, and most of all, fighting spirit and leadership. Keegan has produced another masterpiece, which all military historians and commanders, and historians of the mysterious arts of espionage, must read--and heed, to their peril if they do not.