Battle of Tannenberg (1914)
One of the first engagements of the First World War was the Battle of Tannenberg in 1914. Tannenberg was on the Eastern front and the battle involved an attempted invasion of East Prussia by the Russian army. It ended with victory for the German defenders against overwhelming hostile forces. We have an extensive account by ex-intelligence officer, Wilhelm Flicke, of the battle in which he places signals intelligence derived from wireless in a decisive role [Flicke (1945 [1953])]. In, War Secrets in the Ether, he gives many examples of wireless intercepts directly informing military decision-making on the German side.
According to Flicke, this was the first realisation of the importance of signals intelligence as a real time modifier of military action. However, all of Flicke’s writing requires ‘calibration’ because of his profound anti-Nazi ideology and the potential this has for bias in his account[1]. Other independent accounts show that logistical pressures led to compromise of supplies and procedures, such as the abandonment of cryptographic practices. Bruce Norman claims that the reason the Russians fell back to unenciphered wireless was because of incompetence over a new high-grade cipher: the only copy was given by the commander of the first army to the commander of the second army, and the old cipher destroyed, so the two armies could no longer communicate securely [Norman (1973) p61]. This seems ludicrous. There may, instead, have simply been insufficient resources in the Russian armies for wireless telegraphic communications (and also telephony) to be effective in battle. There may also have been little appreciation of the security vulnerabilities of wireless at this early stage in its development. Whatever the background, the intelligence resulting from wireless interception was not decisive to the battle as there were many other adverse influences on the Russian side, such as a lack of aerial reconnaissance and other situation awareness sources, and poor judgement and decision-making at a senior level. The German side simply suffered from less of these defects. Tannenberg 1914 tells us that signals intelligence can play an important role in battle, but as part of a bigger picture driven by resource availability and quality, efficiency of logistics, and effectiveness of decision-making. Apparently, ‘luck’ is recognised in military circles too. Tannenberg 1914 is certainly an interesting case study in early tactical military radio signals intelligence.
[1] Flicke wanted to demonstrate the futility of totalitarian miliary aggression in his writings. This may taint his recollection of events. His account of Tannenberg is further brought into doubt because the relevant part of the manuscript had to be re-written from memory following the loss of the originals in WWII. This creates scope for idealising the evidence. Interestingly, the rights to Flicks’s book were purchased in 1948 by the US Government (presumably to keep sensitive aspects out of the public domain), but it was translated into English in 1953 and eventually declassified and released by the National Security Agency (NSA) in 2014.
Refs:
Flicke, Willhelm, F. (1945 [1953]), War Secrets in the Ether, Translated by Ray W. Pettegill, 1953, Declassified and released by NSA in 2014, https://www.nsa.gov/portals/75/documents/news-features/declassified-documents/friedman-documents/reports-research/FOLDER_264/41761019080017.pdf
Norman, Bruce (1973), Secret Warfare – The Battle of Codes & Ciphers, Purnell Book Services, 1973