Jerzy Borzęcki, Battle of Warsaw, 1920: Was Radio Intelligence the Key to Polish Victory over the Red Army?, JomH 2017, S. 447-468. Die Antwort ist ambivalent. Ja, vieles wurde aufgeklärt. Nein, es bestand zT kein Vertrauen in die Ergebnisse der Radioaufklärung. Nein, es wurde zT ohne Berücksichtigung der Aufklärungsergebnisse entschieden. Ergo: ein wichtiger Faktor, aber "not absolutely crucial". ... aus dem Text: To conclude, radio intelligence was an important factor in the Battle of Warsaw; it gave the Poles a significant advantage over the Soviets. The Polish radio intelligence service intercepted virtually all Soviet radio traffic and was able to decipher it, usually within a day. Thus Polish generals, and especially the commander in chief, Józef Piłsudski, knew a lot about the Soviet formations they faced. In the case of the Soviet Fourth Army, for example, they knew its numerical strength with great precision. Most importantly, they were usually well informed about Soviet operational plans and their execution. The Polish First Army, defending Warsaw from the east, knew exactly when and where to expect the attacks of the Soviet Sixteenth Army. The Poles learned the intention of the Soviet Fourth Army’s two brigades to strike at the rear of their Fifth Army and were ready for it. They were aware of the Soviet decision to transfer Budenny’s First Cavalry Army to the Western Front and the difficulties in doing so. They also knew the Soviets had intercepted their order with the plan of a major counteroffensive. Finally, during the second phase of the battle, Polish radio intelligence kept jamming Soviet radio traffic, thus making it difficult for the enemy to organize an orderly retreat. Radio intelligence, however, did not answer all of the questions asked by the Polish command. This was seen especially on the eve of the battle when Polish generals, including Piłsudski, wrongly assumed that the main weight of the Soviet attack on Warsaw would come from the east. As a result, the deployment of Polish forces was far from optimal. Sometimes, too, Polish generals did not properly use the information supplied by the radio intelligence service. General Haller maintained the imbalance between his larger First and the smaller Fifth Army, for example, even though he knew the latter was facing much stronger enemy formations. In other cases, the cipher section decrypted Soviet radiograms late, and radio intelligence sometimes was delivered late to the units concerned. Either way, the acquired information was useless. Polish generals did not always fully trust radio intelligence either. On the eve of the crucial counteroffensive, for instance, Piłsudski found the information on the Mozyr Operational Group too good to be true.