When the Imperial Russian Army set out to invade East Prussia in 1914, there were few communication options for the force attacking out of Poland. Roads were a mess in good weather and impossible in bad weather. Telephone and telegraph lines were deemed too vulnerable. Gen. Alexander Samsonov, commander of the 2nd Army, decided to rely on his headquarters and corps-level field radio transmitters. However, because the Russian army had forgotten to distribute any code books to its constituent commands, all of their wireless traffic was unenciphered.
The downstream consequences of that oversight are called “the 20th Century.”
Perhaps you think I exaggerate. Consider the two men whose heroic reputations were founded on the subsequent victory at Tannenberg. Paul von Hindenburg and his adjutant, Erich Ludendorff, became instant heroes, and by 1917 they were running Germany as a military dictatorship. That is when Ludendorff had the brilliant idea to send Vladimir Lenin home to Russia. Several years later, Hindenburg had the brilliant idea to make Adolf Hitler Chancellor of Germany. In each case, they thought they could control the creature they had created. Someone should have stopped them much earlier. Indeed, Ludendorff also chose to ignore tank development, botched the aviation budget, and launched his climactic Operation Michael with “no realistic conception of how to end the war,” according to historian Gerhard Gross. So it is unsurprising that in his own memoir, Ludendorff chose to deprecate the role of signal intercepts in their signal victory at Tannenberg.
That unencrypted Russian radio transmissions made the crucial difference seems undeniable. For example, it was only after First Army broadcast its inactivity that Hindenburg and Ludendorff understood their plan to entrap and destroy Second Army might actually work, and began frantically signaling their own corps commander to attack the Germans on his front. “At 9:45 a.m.,” Dennis Showalter relates in his book on the Battle of Tannenberg, the more famous leaders ordered Gen. Otto von Below to close with the enemy “at all costs.”
This time Ludendorff took no chances. A phone call sent a plane from Air Detachment 16 northeast. Its crew, guiding on the spiked helmets, tossed out copies of the new order over the marching columns. Instead of waiting on the chain of command, the commander of Below's leading division informed the corps commander of the change in orders and promptly turned his men south. By that time, 11:30 a.m., Below had received the orders himself, by both aircraft and phone. "Just like a war game" he commented as he and his staff determined the new lines of march.
Two things are noteworthy here. First, the German doctrine of Auftragstaktik, in which operational commanders were allowed to make decisions without asking permission of higher commands, was being challenged by new technologies such as aircraft. In 1914, they were seen as a means of communicating orders to subordinates who were far away, and unable to see the larger picture at headquarters. Second, the German commands were still not using their own radios just yet, so the Russians did not have the same benefit of poor German COMSEC that the French enjoyed, at least not at this point.
The story of the battle itself is well-known. Surrounded, 90 percent of Russia’s Second Army was killed, wounded, or captured. Upon realizing the extent of the disaster, Samsonov ordered the radio set dismantled, excused himself from his officers, walked into the woods, and shot himself. German doctrinal thinking was obsessed with the kesselschlacht, or cauldron battle. Alfred von Schlieffen, author of the plan to invade France, idolized Hannibal’s victory at Cannae as the very model of a kurtz und vives (“short and lively”) war. Contrary to the failures of their rival generals in the west, Hindenburg and Ludendorff had supposedly won the ideal battle — not just a great victory, but the perfect victory that German doctrinehad been designed to achieve.
The fighting was not over. As they redeployed to expel First Army from East Prussia, 8th Army was forced to use their own radios, and their COMSEC practices were no better. Indeed, the same radio station at Königsberg that intercepted Second Army’s transmissions now overheard Russian wireless operators reporting their own interceptions of German radio traffic.
This is a subtle point that bears explanation: 8th Army had a view inside the decision cycle of Second Army, and then a view inside the intelligence cycle of First Army. It is an advantage to know what the enemy intends, and yet another advantage altogether to know what information is shaping their decisions. It becomes possible to mislead the enemy and know whether your gambit is having the intended effect. Thus, 8th Army headquarters dispatched orders by ground to send false transmissions during the series of bloody slaughters known as the Battles of the Masurian Lakes. Snookered by the deception, Russia was thrown out of East Prussia, and no Russian army would return to German soil until 1945. Rather than “steamroller” the Germans, the Russian army had been halted by its own radio practices.
These battles were the beginning of the end for the Romanov dynasty. At Stavka, the Russian general headquarters, the failures of 1914 would transition into the defeats of 1915, requiring scapegoats. When hanging traitors and deporting Jews to Siberia didn’t work, Nicholas II foolishly set aside his uncle and took command of Stavka himself, owning the failures of 1916 as he was forced to abdicate. Although Russian COMSEC practices belatedly improved, radio SIGINT would remain a vital force multiplier for both Central Powers against Russia until the end of the war.