Polish cryptologists reveal they have cracked the Enigma code: 26 July 1939 Posted on: 26 July 2019 ‘Il y a du nouveau’ On 26 July 1939, in the Pyry Forest south of Warsaw, Polish cryptologists revealed to their British and French counterparts that they had been reading German signals traffic, transmitted by Enigma machines, since 1933. At a previous Enigma machine meeting in January, they had been reticent: but since then the threat from Nazi Germany had increased greatly. Hitler’s takeover of Czechoslovakia in March led to a British guarantee to come to Poland’s aid if attacked. But as SS troops flooded Danzig and German forces massed on the borders, the Polish General Staff were keen to tighten the links with Britain and France. The head of the Polish Signals Bureau sent a coded message to his French counterpart on 30 June that ‘there is a new development’. This was not a cryptologic breakthrough, but a willingness to reveal the secret of the Enigma wiring sequence. Bletchley Park’s ‘Dilly’ Knox, while furious that the solution was one he had rejected, realised the importance of the Polish achievement, which shortened the British attack on Enigma by at least a year.1 At this time MI5 and the Secret Intelligence Service (named MI6 to sound more military as war approached) were struggling to expand operations with scarce resources. This made the Government Code & Cypher School’s achievement particularly valuable. ‘Fire escapes and fire extinguishers’ Poland was not the only country looking for supportive friends in July 1939. Britain and France, alarmed by the increasing closeness and strength of the Berlin-Rome-Tokyo Axis, were trying to reach agreement with Turkey on co-operation in the event of hostilities in the Mediterranean. Istanbul, however, was hedging its bets in order not to alienate Berlin or Moscow. Italian claims of an imminent alliance with Spain, where Franco’s nationalist forces were now in control, increased the alarm felt in London and Paris. During June and July, Anglo-French talks in Moscow aimed at securing a common front with the Soviet Union against Axis aggression progressed slowly. They were spun out by Foreign Minister Molotov who was adept in securing concessions (seeking a free hand in the Baltics) while giving none. William Strang, sent out by the Foreign Office to help, wrote that the negotiations with Moscow were
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