This is a fascinating book on a fascinating subject, written by a master of his craft as a military historian. Sir John Keegan’s declared purpose is to answer a simple question: ‘How useful is intelligence in war?’ The answer he gives is that, however useful intelligence is in disclosing the enemy’s intentions, strengths and weaknesses, wars are won not by knowledge but by brute force in battle. The modern fad to give primacy to knowledge he rejects as misleading. Addicts of spy fiction will be disappointed. Spies rarely supply relevant information in time for it to be of use. This book is not cloak and dagger stuff but a superbly researched series of case studies on the use of intelligence in war from the 18th century to the present war against terrorism.
Keegan’s first case study is Nelson’s 73 weeks’ chase, backwards and forwards across the Mediterranean, of Napoleon’s fleet in 1798. He operated in the days of sail when ‘the sea was an area of the unknown’ and discovery of the enemy dependent upon sight. On scraps of information, he came to the conclusion that the French fleet would make for Egypt. But with imperfect intelligence he made false guesses as to its route. Having found his enemy it was his ‘killer instinct’ that gave him, in the Battle of the Nile (6 August 1798), ‘a crushing victory never exceeded during the days of sailing-ship warfare’.
Nelson’s difficulties, dependent as he was on sight from a topmast, would have been lessened had he possessed the technical triumphs of the post-electronic age: the telegraph, the radio and aerial photography and today’s satellites. Keegan’s account of the successes of Bletchley Park’s Code and Cipher School in cracking the fiendishly coded messages sent by the Enigma machine is of absorbing interest. I must confess that I found the mathematics and mechanics of code-breaking tough going. Not so the description of the extraordinary community of mathematical dons of genius and aristocratic ladies who could keep their traps shut. It is astonishing that Bletchley’s activities remained a secret until 1972, something inconceivable in our leaking age.
What was the use made of this mass of information available in the second world war? In the Cretan disaster of May 1941, vividly described by Evelyn Waugh, General Freyberg knew, from Bletchley’s decrypts, that he would be confronted by an airborne invasion.
‘Intelligence is only as good as the use made of it.’ Freyberg lacked the clarity of the German commanders’ aim. In 1917 the German U-boats almost succeeded in starving us into surrender. The possibility that Admiral Dönitz (to Keegan a genius, if an evil one, the inventor of the patrol lines by day and the wolf pack that would attack convoys in swarms by night) might succeed where the Germans had failed in 1917 was for Churchill ‘the only thing that really frightened me’. Superior intelligence was provided intermittently by Bletchley, undoubtedly giving strategic and tactical advantages. But intelligence was ‘one factor among many’ and ‘though significant, was secondary to the age-old business of fighting it out.’ By May 1943 Dönitz had lost the battle of the Atlantic. In that grim struggle 30,000 allied merchant seamen and 28,000 U-boat crews died ghastly deaths.
The battle of Midway of 4 June 1942 was a decisive encounter. With the destruction of Admiral Naguma’s aircraft-carriers, Japan lost mastery of the Pacific. US cryptanalysts revealed where and when in the vast expanse of the Pacific Naguma’s fleet would appear. But was it, Keegan asks, ‘a complete intelligence victory’? Not quite. The greatest writer on war, Clausewitz, held that war was the province of uncertainty. A chance visual sighting of a destroyer returning to the main fleet allowed US bombers to catch Naguma with his aircraft below deck or unable to fly with the decks littered with planes and oil hoses. Three carriers would be destroyed in five minutes. The battle could have gone either way, but, as the Harvard-educated Admiral Yamamoto saw, the vast power of the US would give it victory in the end. Midway shortened the time in which victory could be achieved. Once more, intelligence was one factor among many.
I have given only a selection of this book’s case studies. Keegan’s essential message is abundantly and repeatedly stated: ‘Victory is an elusive prize, bought with blood rather than brains.’ It was ‘the almost mindless courage’ of the German soldiers in Crete ‘who preferred collective death to defeat’ that brought victory. But Keegan has other messages. In the war against fundamentalist Islamic terrorists there is no visible opponent as in conventional warfare. To win we may be driven back to the world of John Buchan and Kipling, infiltrating the enemy by agents with the linguistic skills and knowledge of the opponent’s culture that will enable them to go native. Such men are in short supply. Finally Keegan argues that subversion should not be confused with intelligence. Churchill’s admiration for Boer guerrillas led him to believe that Europe could be ‘set on fire’ by the agents of the SOE parachuted into occupied Europe. The operation was costly of brave lives and its efficiency in producing results is still the subject of debate.
I warmed to this book because it is suffused with the old-fashioned virtue of patriotism. Nelson is ‘the greatest admiral who ever lived’; Philby, Burgess et al are traitors whose disordered and sordid lives reveal a rottenness at the heart. I knew Burgess well and endured his harangues on the virtues of the Soviet Union, which surprised me in a man known to be working in British intelligence. One hopes that Keegan is correct in thinking that today a traitor will not be protected by ‘the indulgence felt by the well behaved for the professional naughty boy’.