Adolf Hitler's plans for a surprise attack and occupation of Switzerland, which were due to take place at the start of 1941, have been brought to light by a German historian.
In his book "Hitler und die Schweiz" ("Hitler and Switzerland"), Stefan Schäfer examines documents stored in the Federal Archives and in the German Military Archives containing details of a planned attack, which he believes posed a serious threat to Switzerland's independence.
According to Schäfer, a historian from the Martin Luther University in Germany, one of the main reasons why Switzerland was not invaded was because of the ceasefire between France and Germany, which France was forced to accept following the German offensive in May and June 1940.
Schäfer maintains that if the campaign against France had continued, Switzerland would have suffered a full military onslaught by Nazi forces, which planned to use the territory to reach the unoccupied zone in the south of France and the Mediterranean as quickly as possible.
Switzerland had mobilised some 450,000 troops in anticipation of a German invasion.
"The Swiss tend to believe that they survived the Second World War because the country supplied Germany with the hard currency necessary for its war effort," says Schaefer. "However, the military threat hanging over Switzerland at the time would suggest the opposite."
Ceasefire with France
Hitler apparently ordered his military staff to start drawing up plans for what would later be known as operation Tannenbaum, just days before a ceasefire with France was signed, on June 22, 1940.
The plans for the invasion were finally approved in October 1940. The date for the offensive was kept under the strictest military security as the Germans aimed to use the element of surprise to break Swiss resistance as swiftly and effectively as possible.
The Nazis aimed to destroy the Swiss Confederation army and invade the central part of Switzerland, which was important for strategic and economic reasons. The Solothurn region, for instance, was considered an important base for the production of armaments.
While the occupation of Switzerland was not one of Hitler's primary objectives in the campaign against France, its location between the Third Reich and its ally, Italy, made it likely that the Nazis would eventually annex Switzerland.
Had this been the case, concludes Schäfer, Hitler would have successfully rounded off his campaign in Western Europe.