Probably more than any other politician of his era, Winston Churchill understood how to exploit, and benefit from, secret intelligence. His experience as a London Times correspondent in South Africa made him aware of the importance of timely and accurate intelligence, and his appointment as home secretary in 1910 gave him his first access to the classified reports drawn up by MI5. As first lord of the admiralty Churchill saw at first hand the impact of the cryptographic breakthroughs achieved by the code breakers of Room 40, who were his ministerial responsibility. The Admiralty’s success in reading many of the enemy’s communications, and the Royal Navy’s development of intercept and direction-finding techniques, severely handicapped the kaiser’s fleet and allowed his Zeppelin airships to be intercepted by British fighters.
Perhaps more significantly, the coup of supplying the Americans with the key to the German diplomatic cipher so they could read the content of the Zimmermann telegram for themselves proved to be a turning point in the war and led to the entry of the United States into the conflict in 1917.
As well as appreciating the need for secret intelligence and the importance of protecting its often fragile sources from compromise, Churchill enjoyed the company of those who worked in the shadows and understood the advantage their inside knowledge gave him. During the interwar period, he came to rely heavily on a Secret Intelligence Service officer, Desmond Morton, and Churchill’s campaign to rearm Great Britain stemmed largely from his access to SIS assessments of the growing military threat from the Nazis.
Although many in the British intelligence community were deeply suspicious of Churchill and his motives, he was quick to grasp the potential significance of the early research undertaken on the Enigma machine, and when he was elected prime minister, Churchill insisted on a daily personal briefing from “C,” Stewart Menzies, so he could read a selection of the latest intercepts before they had been processed and sanitized.
Churchill would refer to the cryptanalysts at Bletchley Park as “the geese who didn’t cackle” and responded instantly when a group of senior staff complained to him about a lack of resources. Their ULTRA product gave the Allies a decisive advantage in sweeping the Afrika Korps from North Africa, in the Battle of the Atlantic against the U-boats, and in the elimination of German surface raiders. While ULTRA may not have won World War II, it certainly shortened the conflict by as much as two years, and Churchill’s determination to protect its integrity, while extracting the maximum from it, was critical.