Operation Tannenbaum

Operation Tannenbaum ("Fir Tree"), known earlier as Operation Grün ("Green"), was a planned invasion of Switzerland and Liechtenstein by the Axis powers during World War II.

Before the outbreak of the Second World War, Adolf Hitler made repeated assurances that Germany would respect Swiss neutrality in the event of a conflict in Europe. In February 1937, he assured the Swiss Federal Councillor Edmund Schulthess that "at all times, whatever happens, we will respect the inviolability and neutrality of Switzerland", reiterating this promise shortly before the German invasion of Poland. These were, however, purely political maneuvers intended to guarantee Switzerland's passivity. Nazi Germany planned to end Switzerland's independence after it had defeated its enemies on the continent.

In a meeting held with Fascist Italy's leader, Benito Mussolini, and Foreign Minister Galeazzo Ciano, in June 1941, Hitler stated his opinion on Switzerland quite plainly:

"Switzerland possesses the most disgusting and miserable people and political system. The Swiss are the mortal enemies of the new Germany."

In a later discussion, the German Foreign Minister Joachim von Ribbentrop directly alluded to the possibility of dividing Switzerland between the two Axis powers: "On the Duce's query whether Switzerland, as a true anachronism, had any future, the Foreign Minister smiled and told the Duce that he would have to discuss this with the Führer."

In August 1942, Hitler further described Switzerland as "a pimple on the face of Europe" and as a state that no longer had a right to exist, denouncing the Swiss people as "a misbegotten branch of our Volk." From a Nazi viewpoint, Switzerland, as a small, multilingual, decentralized democracy where German-speakers felt more of an affinity with their French-speaking fellow Swiss citizens than towards the German speaking people living across the border, was the antithesis of the racially homogeneous and collectivised "Führer State". Hitler also believed that the independent Swiss state had come into existence at a time of temporary weakness of the Holy Roman Empire, and now that German power had been re-established after the National Socialist takeover, the independent country of Switzerland had become obsolete.

Although Hitler despised the democratically minded German Swiss as the "wayward branch of the German people", he still acknowledged their status as Germans. Furthermore, the openly pan-German political aims of the Nazi party called for the unification of all Germans into a Greater Germany, which included the Swiss people. The first goal of the 25-point National Socialist Program stated that "We [the National Socialist Party] demand the unification of all Germans in the Greater Germany on the basis of the people's right to self-determination."

In their maps of Greater Germany, German textbooks included the Netherlands, Belgium, Austria, Bohemia-Moravia, the German-speaking parts of Switzerland, and western Poland from Danzig (Gdańsk in Polish) to Krakau (Kraków). Ignoring Switzerland's status as a sovereign state, these maps frequently showed its territory as a German Gau. The author of one of these textbooks, Ewald Banse, explained: