In war, if you know what the enemy is going to do, you've won. Right? That's not necessarily so, as the British showed in the German invasion of Crete. John Keegan's Intelligence in War uses this as just one example of how intelligence is used in wartime, and how it has not always the end-all and be-all of how a battle is won. Keegan explores the entire gamut of intelligence and how it has been gathered and used in modern warfare, using examples ranging from Admiral Nelson's chase of Napoleon's fleet on its way to Egypt in 1799 to some World War II examples. He finishes the book by discussing modern techniques ranging from Vietnam to the war on terrorism. It is a fascinating book that upends historical stereotypes.
"Its theme is that intelligence in war, however good, does not point out unerringly the path to victory. Victory is an elusive prize, bought with blood rather than brains. Intelligence is the handmaiden not the mistress of the warrior." (p. 5)
Methods of intelligence acquisition range anywhere from "humint" (the garnering of intelligence through human means -- usually spying, but also including local knowledge of the area) and "sigint" (the interception of signals, whether radio satellite or semaphore flags). As technology has increased, the use of humint has decreased as more signals, and more ways of intercepting those signals, have been developed. The problem in the past has always been conveying the intelligence found to superiors before it becomes outdated. The first case study, Nelson and Napoleon, demonstrates this completely, with Nelson getting increasingly outdated information and making some choices based on false assumptions of what he knew, but ultimately prevailing because of a decisive mind willing to take a chance on suppositions based on that intelligence. Keegan does an excellent job here showing the troubles Nelson had to go through to even get what he had.
Other case studies include Stonewall Jackson and his Shenandoah Valley campaign (demonstrating local area knowledge), the chasing of the German surface fleet in World War I (the interception and use of wireless signals), the battle of Crete (how intelligence doesn't always win the battle), the battle of Midway (the breaking of Japanese codes), the battle of the Atlantic (how intelligence was just one part of the defeat of the German submarine fleet), the German V-1 and V-2 rocket campaign against Britain (how human intelligence became very important) and then an evaluation of military intelligence from 1945 to today. Keegan concludes that war is not won just by intelligence, but by brute force.
"Nevertheless, few who make war at any level, from commander to the soldier in the line of battle, seek to win by attrition. All hope for success at lesser cost. Thought offers a means of reducing the price."
The broad examples Keegan uses to illustrate his point takes the reader gently along the path to understanding. He first shows some instances where intelligence was instrumental in helping the winning side succeed in their action (Nelson surprised the French fleet at Alexandria and destroyed it). He then shows us Crete, and how the British knew almost the entire German plan, but misinterpretation of parts of it kept the local commander from deploying his forces correctly, causing the loss of the island even though the Germans lost forty percent of their paratroopers. This brutally enforces Keegan's notion that intelligence is nothing without the blood and sweat necessary to make use of it, or how that same blood and sweat given by the enemy can overwhelm even a prepared force.
Even without the intelligence theme running through the case studies, they are fascinating history. Keegan tells the story completely even as he uses each chapter to illustrate his point. While at times the entire chapter is illustration (the Nelson chapter continually refers to the intelligence that Nelson had received and figured out), other times he seems to abandon the theme and just tell the history (the Jackson chapter and the Battle of the Atlantic). Doing this in the Atlantic chapter reinforces the fact that, while intelligence was important in the fight against the submarine wolf packs, it was the sailors who were the most important in winning this particular battle.
Keegan's research is top-notch, though there are times you wonder about the variety (or lack thereof) of sources he uses for a particular chapter. The number of "ibid" notations can be quite alarming sometimes, though he always uses at least five or six sources for any one chapter. I do notice that there aren't any primary sources (though some of the notes say "quoted inů," so the text he is using as a source may have been using a primary source). While this is an issue, it does not seem to be a major one in this case. He is not trying to tell a definitive history with his case studies, but to use them as support of his thesis about intelligence. He is not trying to get into the heads of parties involved. Some readers may have a problem with that, however.
Keegan's style is layman-friendly. The chapters flow effortlessly, and if you have any interest in the subject whatsoever, you should find yourself intrigued. You may not agree with him, but you will not have any trouble getting through the book. It is not dense at all, although it is a thick book, at almost 400 pages before notes and bibliography. Personally, I couldn't put it down, but Keegan always entrances me with his writing. Read this book, and discover just how important intelligence is in warfare, and how sometimes it just isn't enough.