Inferno: The World at War, 1939-1945

by Max Hastings

But what mattered was that Rommel was denied a breakthrough—although, given the opposing forces’ respective strengths and detailed Allied foreknowledge of German intentions, it would have been disgraceful had he achieved one. In the first days of August Churchill arrived in Cairo with Gen. Alan Brooke, to see for himself how things stood. He sacked Auchinleck, who was replaced as Eighth Army commander by Brooke’s nominee, Lt. Gen. Sir Bernard Montgomery, and as Middle East C-in-C by Gen. Sir Harold Alexander. A month later, on 30 August, Rommel attacked at Alam Halfa. Montgomery, provided by Ultra with full details of German plans, drove him back. The general then addressed himself to training Britain’s troops for his own offensive. He had two critical advantages: large U.S. tank reinforcements were arriving and the Desert Air Force had gained dominance of the sky. THE VOLUME of Ultra intelligence was now increasing dramatically, with critical influence in every theatre. In earlier years, decrypts were priceless, especially to the naval war, but their flow was erratic. From mid-1942 onwards, with a few important breaks, the Allies became privy to much of their enemies’ signal traffic; the penetration of German and Japanese ciphers made a massive contribution to victory. Beyond the achievements of British and American decrypters, it was a secondary miracle that the Axis powers never seriously suspected that their most secret communications were being accessed by the enemy. ...