Since the 1930’s a segment of German society that opposed the National-Socialist regime had tried to establish contact with foreign countries in order to topple Hitler. During the war the same groups contacted US and British officials in neutral countries and tried to gain their support in order to remove the NS regime from power. The Western Allies were aware of these efforts but they did not offer material support to the members of the German resistance.At the same time elements of the NS regime came to realize that the war was lost and thus made cautious attempts to contact Allied officials that could promote some sort of compromise peace. Heinrich Himmler was leader of the SS security service and thus one of the most powerful men in Nazi Germany. Yet by 1943 he was beginning to realize that hopes for a successful conclusion of the war were slim. His subordinate General Walter Schellenberg, head of the foreign intelligence department of the Sicherheitsdienst, had many talks with Himmler on the need for a compromise peace and in 1943 he was able to make the first attempts at contacting Allied officials.
The Germans knew that Allen Dulles was in charge of the OSS-Office of Strategic Services station in Bern, Switzerland and they chose to contact him through people associated with the German resistance.In early 1943 Prince Max Hohenlohe (working on behalf of the Sicherheitsdienst) was given permission to travel to Switzerland and meet Dulles. Unfortunately it doesn’t seem like their meeting remained a secret for long. In the Finnish national archives one can find the decoded version of message No 2.181 of April 7, 1943, giving an overview of their discussion.
Both the German resistance (through Admiral Canaris) and the Sicherheitsdienst (through Schellenberg) had warned Dulles that his communications were compromised but it doesn’t seem like he acted on this information. These efforts for a compromise peace were probably doomed from the start (especially since the Germans seemed to have overestimated the influence of Dulles) but even so without secure communications the talks could not have remained secret for long.