Military wireless intercept organization is a massive, complex system. The Allies simply did a better job of getting all the parts to work together.
The signals intelligence effort in World War 2 was huge. By my count, over 100,000 service men and women worked in wireless intercept. Another 30,000 did code breaking. Matters of organization, training and equipment were daunting. All forces had access to similar techniques and technologies. However, it was the ability of the Allies to adapt, coordinate and eventually act on their signals intelligence that made the biggest difference.
The British were the most advanced. Obviously so in decryption. A centralized decoding organization grew out the first world war. This was the Government Code and Cipher School (GCCS). By 1923, Britain centralized coordination of wireless intercept (Y Service). Various joint forces committees were set up. The most effective of these was the Y Service Sub Committee. It tasked radio intercept facilities across the Empire.
Combatants spread wireless intercept duties across all service branches – army, navy, and later air force – as well as counter-intelligence on the home front. By the time war started, much experience in signals intelligence had been gained over the previous decade, particularly Britain and Germany.
The Americans were late to the game. An unfortunate State Department directive in 1929 set them back: “Gentlemen do not read each other’s mail”. Subsequent funding cuts in State, however, were offset by a shift to military intercept. The U.S. Army Signals Intelligence Agency was formed in 1930 and, together with the Navy, monitored Japanese diplomatic – but not military – traffic extensively. When America entered the war, though, it had no central control of monitoring, enormous rivalry between its monitoring branches, and no centralized cryptography.
Even before Pearl Harbor, Britain (especially Churchill) recognized the importance of SIGINT and getting the U.S. up to speed. Britain shared what it knew and did extensive training of American radio intelligence staff. By 1943 the Americans were adopting proven coordination and information sharing techniques and were gradually integrated into the joint committees.
On the Axis side, wireless intercept was centrally controlled by the High Command. The Japanese Navy did the lion’s share of reading the mail through its Communications Units. The Germans paid particular attention to building intercept capacity, in part to compensate restrictions on the size of their forces. By 1930 they were covering all frequencies. Germany was especially focused on using traffic analysis to understand the size and disposition of foreign forces.
Wireless Intercept Organization Acceptance
Armed forces are large and bureaucratic. It took a while for SIGINT value to be recognized, especially at the tactical level. Before the war, signals intelligence was viewed as a peacetime activity with no place at the front lines. At first, the degree of cooperation was highly dependent on personal relationships and preferences. For the United States, the breakthrough came at the Battle of Midway. This effort “moved signal intelligence from an arcane, little-understood, and usually unappreciated specialty to the very center of military operations”. For Germany, Rommel’s early success in North Africa arose from his attention to traffic analysis.
But Germany routed all radio intercepts to High Command and then back down to field commanders. Often, the information provided to the field was colored by the Fuhrer’s interpretation and desires, rather than the facts. According to General Praun: ” throughout the war General Jodl, as well as Hitler himself, frequently showed a lack of confidence in communication intelligence, especially if the reports were unfavorable. Even though the information submitted to higher headquarters did not lead to the logical tactical, strategic, and political decisions, communication intelligence cannot be blamed for the subsequent events.”
In summary, Allied intercept organization was “more unified at the top and operationally intimate below.” Even putting Ultra aside, Allies were better at using radio intercept to their advantage.