Operation Tannenbaum: Germany's WWII plan to invade Switzerland that never happened

During World War II, Switzerland maintained its neutral stance, staying impartial as the rest of Europe was consumed by conflict. Recognizing the imminent threat of invasion, the nation adopted several defensive strategies. Yet, one question remains: Why did the Germans ultimately choose not to invade its borders?

History of Swiss neutrality

Switzerland's position of neutrality during World War II wasn't a new stance. The roots of the country's commitment to neutrality stretch back to the 16th century and the Battle of Marignano . After the Swiss Army's defeat to the French in September 1515, a deliberate decision was made to avoid joining in future conflicts, prioritizing self-preservation.

Despite this longstanding dedication to neutrality, Switzerland encountered challenges to its position over the centuries, mainly due to the actions of other nations.

Formally declaring neutrality during the Congress of Vienna in 1815, Switzerland upheld this principle during World War I by refraining from direct military engagement. Nonetheless, the nation provided asylum to refugees and activated its armed forces. Internal tensions among the French-, Italian-, and German-speaking communities also emerged.

Following WWI, the League of Nations , established by the victorious powers, recognized and respected Switzerland's neutrality, establishing its headquarters in Geneva.

A promise from Germany, to Switzerland

Switzerland's neutrality appeared secure during the rapid ascent of the Führer , who guaranteed that their status would be honored. In a meeting in February 1937, he even assured Swiss official Edmund Schulthess that Germany would not invade the country. Yet, these assurances proved as stable as a house of cards. Throughout the war, Germany quickly took control of neighboring nations- Denmark , Luxembourg , the Netherlands , Poland , Norway and Belgium were all occupied.

Fully aware of Germany's brutal strategies, Switzerland chose to proceed with caution and mobilized its military. At its height, the Swiss force grew to an impressive 850,000 soldiers , all under the leadership of Henri Guisan, a distinguished veteran with a remarkable career in the Swiss Armed Forces.

Guisan led the National Redoubt strategy, a defensive plan that called for the deployment of three mountain brigades and eight infantry divisions. These troops underwent intense training that mirrored the harsh battles occurring across Europe. The strategy, in the event of an invasion, was for the Swiss government to relocate to the Alps, thereby safeguarding both territory and political authority.

The planning of Operation Tannenbaum

Despite the Führer ’s assurances to Switzerland, the country firmly maintained its stance of absolute neutrality. This act of defiance infuriated the German government, leading them to develop plans for a possible invasion.

The Führer , with disdain , expressed to Italian Prime Minister Benito Mussolini , "Switzerland possesses the most disgusting and miserable people and political system. The Swiss are the mortal enemies of the new Germany."

The invasion plan, known as Operation Tannenbaum , involved a division of the Wehrmacht , stationed in Central France with two million soldiers, advancing into Switzerland. Italian forces were also included in the strategy. While German troops were tasked with capturing Geneva and Lucerne, the Italian Army was to invade through the Alps, with the goal of dividing Switzerland between the two powers.

Despite the overwhelming military strength of Italy and Germany, which could have easily overrun Switzerland, Operation Tannenbaum was never carried out for reasons that remain unclear.

Why didn't the Germans move forward with Operation Tannenbaum ?

Germany's defeat in World War II and the death of the Führer closed the door on discovering the exact reasons behind the abandonment of Operation Tannenbaum. Consequently, historians have turned to various theories to explain this decision.

One theory suggests that, despite its smaller military size, Switzerland was well-equipped for a strong defense; its investments in weaponry had given it one of the most advanced arsenals of the time. The country's geographical features, such as its landlocked position, lack of navigable waterways and rugged mountainous terrain, made it challenging for military operations, much less an occupation.

Another theory suggests that Germany found Switzerland’s neutrality advantageous. The Swiss served as a conduit for laundering stolen gold, and the nation also offered a potential refuge for German officials if the conflict's outcome turned unfavorable.

Switzerland remains neutral to this day

Despite the challenges, Switzerland managed to stay neutral during the whole of the Second World War. Since then, the country has largely stayed out of major conflicts, with the exception of the War in Afghanistan . This was the first time Switzerland engaged in combat since 1815. Additionally, during the War in Iraq , Swiss officials allowed American forces to use Swiss airspace for surveillance missions.

Want War History Online 's content sent directly to your inbox? Sign up for our newsletter here!

In 2022, then-President Ignazio Cassis outlined Switzerland's position, stating that the country's values consist of "no participation in wars; international cooperation but no membership in any military alliance; no provision of troops or weapons to warring parties and no granting of transition rights."