Wilhelm Flicke worked in German cryptologic organizations, as an analyst and administrator, from World War I through World War II. The rights to his Kriegsgeheimnisse in Aether, which covers both wars, was purchased by the U.S. Government shortly after World War II.  The following is his account of radio intelligence intercept of the West.

The campaign in the West in the summer of 1940 appears too many people to be the master stroke of a military genius. Even when we take into account the German superiority in numbers and materiel and appraise adequately the spirit of the German troops, many things still remain inexplicable – in particular the swift drive through the northern continuation of the Maginot Line. On the basis of what I was able to learn, I shall attempt to throw a few side lights on this campaign, without pretending to be able to explain everything.

I have already reported on the situation in the intercept service. Conditions for successful intercept work were as favorable as one could desire in France, Holland, and Belgium.

How Good was the Defense System of the Maginot Line?

From intercept traffic the French assembly and the Belgian and Dutch frontier defenses could be recognized so clearly both in respect to organization and geographical distribution that the information was fully adequate for making German dispositions. It was a pleasure for the German command to be able to enter the enemy’s troop dispositions on its own situation maps on the basis of the results of the intercept service. In the present case, however, this did not suffice. Before the war the great question was: how good will the mighty defense system of the Maginot Line be? Will it be possible to break through quickly or will a war of position on a large scale develop here? Will modern heavy artillery be able to crack these defenses? Who could answer these questions?

Earlier we reported how Poland and Czechoslovakia were thoroughly reconnoitered by the German espionage service. In France there was no such degree of success although the German intelligence service did receive current reports and single notices. France had no extensive German minority and conditions were less favorable. Nevertheless, in the summer of 1939 the German Secret Service succeeded in pulling off something which absolutely made up for the previous years. In August it was possible to get a photograph of a French map showing all forts, barriers, obstacles, communications routes and communications points of the Maginot Line and of its extension to the coast. This showed how imperfectly the French had developed their system of defense along the Belgian frontier and one did not need to study the map long in order to put his finger on the weakest point in this system of defense. This map was reproduced in Germany and was the basis for planning the campaign in France.

Hitler Youth boys learning Morse Code.

In order to drive at this weak point in the French system of defense, it was necessary to advance through Holland and Belgium. Consequently, this move was decided upon in Germany without hesitation. The prospect of overrunning the French line swiftly was too inviting, and it was impossible for the French to build up this weak point within a few months to match the strength of the Maginot Line proper.

Cracking Jokes of a Phony War

The campaign against Poland was followed by a period of calm. Only in the air and at sea did some minor engagements take place, which no one regarded very seriously. People were already beginning to crack jokes about the “phony war.” Many thought there would be no serious conflict and that France and England were in a state of war merely “to save face” with respect to Poland. Peace would surely come in the spring.

The monitoring of French and English traffic, however, did not indicate that people in those countries were concerned with “saving face.” War production was under way; they were arming for battle, though only for a defensive struggle. The whole system of land defense for France since 1919 had been based on the invincibility of the Maginot Line, while England was convinced that economic measures directed against Germany would not fail. Anyhow, one could not count on a conciliatory attitude in either France or England.

On 27 January was broadcast Churchill’s speech in which he said: “Hitler has already lost his best opportunity.”

Source: nsa.gov