France was defeated. So too were Poland, Norway, Denmark, Holland, and Belgium. Austria and Czechoslovakia had been incorporated into the Greater German Reich. Great Britain stood alone in her ‘splendid isolation,’ and the fascist regime of Francisco Franco held sway over the Iberian Peninsula. In June of 1940, all that remained, surrounded by enemies, was the Swiss Confederation.

Hitler called it a “pimple on the face of Europe.”[1] In the heady days of victory for the Third Reich, a move against the alpine republic seemed a great possibility – almost inevitable, even. Even before the Fall of France was made official, plans were being drawn up for ‘Operation Tannenbaum,’ the German invasion of Switzerland. Yet Hitler’s attention was soon drawn towards Britain, and eventually the plan fell by the wayside as he began focusing attention on his Bolshevik neighbor to the East.

But…what if? What if Hitler had decided that the conquest of that mountainous pimple was indeed worth the effort and manpower? What if Tannenbaum had been more than just idle words and an OKW plan? If Hitler had embarked on the ultimate folly, the results would have been disastrous for the Swiss – and the Nazis.

For years, the Swiss had had every reason to expect invasion. After Hitler came to power in 1933, he immediately began making overtures towards the various Nazi and pro-Nazi organizations in German-speaking countries (particularly Austria and Switzerland).The Führer warned against possibility of Germany ending her days “as a second Switzerland,” serving others as a “slave nation.”[2] Whether cautionary tale, empty rhetoric, or even plain contempt, the Swiss took Hitler’s remarks – and actions – to heart. Everything seemed to point towards German designs on the tiny alpine nation, despite its centuries-old tradition of neutrality and complete disdain for the trendy “pan-this and pan-thats” sweeping across Europe.

Textbooks in Germany included Holland, Belgium, Austria, Bohemia-Moravia, the German-speaking parts of Switzerland, and western Poland from Danzig to Krakow in maps of Greater Germany (though curiously, neither Denmark nor Norway were ever considered necessary components of this fantastical Reich).

The author of one of these textbooks, Professor Ewald Banse, responded to Swiss criticisms of his maps by explaining: “Quite naturally we count you Swiss as offshoots of the German nation (along with the Dutch, the Flemings, the Lorrainers, the Alsatians, the Austrians and the Bohemians … One day we will group ourselves around a single banner, and whosoever shall wish to separate us, we will exterminate!” Various Nazis were vocal about the German intent to “expand Germany’s boundaries to the farthest limits of the old Holy Empire, and even beyond.”[3]

In response to this bellicosity, a “sharp increase” in defense spending was approved, with a first installment of 15 million Swiss francs (from a total multi-year budget of 100 million CHF.) to go towards modernization. With Hitler’s renunciation of the Versailles Treaty in 1935, this spending jumped up to 90 million CHF.[4] The budget would only continue to rise as war seemed increasingly inevitable, and this lead in turn to the development of several signature Swiss small arms. The K31 became the standard-issue infantry rifle until 1953, and was superior to the German Kar98 in ease of use, accuracy, and weight. By the end of World War II, nearly 350,000 would be produced.[5]

All the branches of the military were in need of modernization, and the Air Force was no exception. The Swiss managed to get the best technology from both parties on the brink of war. The French Morane-Saulnier M.S.406 was produced under license in Switzerland starting in 1938. While the general reputation of the 406 leaves something to be desired, the Swiss managed to upgrade the engine and the propeller, re-designating it the D-3800, and giving it something more of an advantage over the various German fighters of the day.

Somewhat evening the score, and despite the tensions between Germany and Switzerland, the former agreed to sell 90 Bf-109D fighters to the latter, the last of which were delivered just before the invasion of France in 1940. This would prove a costly mistake, as over the course of the war Swiss Bf-109’s shot down eleven German planes that had entered their airspace.[6]

The few Nazis in Switzerland were, despite their numbers, taken very seriously. There is much data to make the case that at least in the early days of the NSDAP, a great deal of funding came from various Swiss sources.

In 1923, Hitler had been invited to give a talk in Zurich by Ulrich Willie, Jr., the son of Switzerland’s World War I commander-in-chief. Hitler returned “with a steamer trunk stuffed with Swiss francs and American dollars.”[7] Two years earlier, a group of “predominantly high-ranking civil servants, university and high school teachers, publicists, some businessmen, and many army officers” had founded the Volksbund für eine unabhängige Schweiz (People’s Union for an Independent Switzerland, or VUS), at first merely to protest Swiss entry into the League of Nations. To the goals of the VUS was soon added the containment of communism in Europe. Thus, there was enough sympathy to generate a not insignificant amount of funding for the NSDAP and other professed anti-communist groups.

The VUS was primarily Zurich-based, but together with likeminded home guards in other regions of the country, the Schweizerischer Vaterländischer Verband (Swiss Patriotic Federation, or SVV) was formed. This slightly pro-Nazi, semi-authoritarian organization could count among its members none other than Henri Guisan. However, as Raffael Scheck points out, the Swiss population as a whole, including many members of the VUS and SVV after Hitler’s ascent to power, was “largely united in hostility to Nazi Germany.”[8]

While the Nazi movement failed to gain a serious foothold in the country, pro-Nazi agitation was seen as a potential precursor to war. Hitler, after all, had relied on far more flimsy pretenses before. The Swiss were not particularly receptive to the idea of a Großdeutschland, and official broadcasts and speeches continually stressed the pluralist, inclusive society that Switzerland had to offer. With its four official languages, Switzerland was proof that a nation did not need to be confined to a citizenry based on ethnicity.

In a message from the Schweizerischer Bundesrat (Swiss Federal Council), the St. Gotthard Pass in the South was held as the embodiment of Europe. The pass, where the Rhône, Rhine, and Ticino Rivers originate, was the spot where the three major cultures of continental Europe – German, French, and Italian – all met. The speech went on to declare:

For the very basis that we reject the concept of race or common descent as the basis of a state and as the factor determining political frontiers, we gain the liberty and the strength to remain conscious of our cultural ties with the three great civilizations. The Swiss national idea is not based upon race or biological factors; it rests on a spiritual decision. The Swiss federal state is an association of free republics: it does not swallow them, it federates them … The respect for the right and liberty of human personality is so deeply anchored in the Swiss idea that we can regard it as its basic concept and can proclaim its defense as an essential task of the nation.[9]

Stephen Halbrook, when not lost in his own ramblings on the necessity of gun ownership, describes the geistige Landesverteidigung of the Swiss, their ‘spiritual national defense,’ as relying entirely on the individual citizen. As a response to National Socialism, the “moral dedication to defense of the homeland and democratic ideas” would be, if necessary, ‘why they fought.’ Federal Councilor Philipp Etter resolved that:

The armed defense of the country is a primary and substantial task of the state. The mental defense of the country falls primarily not on the state but on … the citizen. No…battalions are able to protect right and freedom, where the citizen himself is not capable of stepping to the front door and seeing what is outside [italics mine].[10]

The ideal man to embody these ideals was Henri Guisan.

Switzerland had (and continues to have) a unique form of generalship. In peacetime, there is no officer with a rank higher than that of Oberst (colonel). However, in times of war and ‘of need,’ the Bundesversammlung elects a General to command the army and air force. On August 30, 1939, Henri Guisan was elected with 204 votes out of 227 cast.[11] Despite his membership in the SVV, he would go on to perform admirably, both as a tactician and a morale-booster. Guisan immediately took charge of the situation.

The Wehrmacht invaded Poland three days later at noon, and Britain declared war on Germany at 1210. Guisan called a general mobilization, and issued Operationsbefehl Number 1, the first of what was to be a series of evolving defensive plans.

The first assigned the existing three army corps to the east, north, and west, with reserves in the center and south of the country.[12] Guisan reported to the Federal Council on September 7 that by the moment of the British declaration of war, “our entire army had been in its operational positions for ten minutes.” He also had his Chief of the General Staff increase the service eligibility age from 48 to 60 years old (men of these ages would form the rear-echelon Landsturm units), and ordered the formation of an entirely new army corps of 100,000 men.[13]

In 1938, the Swiss Army had consisted of three army corps, with six infantry and three mountain divisions subordinated to them, plus three mountain brigades. All were commanded by no one higher than the rank of colonel. As 1940 dawned, the Swiss Army had swelled to four army corps and 600,000 men under arms – out of a country of four million.[14] Still, a well-armed citizenry, sizable militia, and possession of that geistige Landesverteidigung would probably not suffice to hold out against the seemingly invincible might of the Wehrmacht.

At the cessation of hostilities in France on June 22, 1940, the German Army in France consisted of three Army Groups containing roughly 2 million soldiers in 102 divisions.[15] Total casualties amounted to 156,492 for the Germans (with 27,000 dead), and 2.2 million for the French (90,000 of them killed).[16] There existed no clear chain-of-command for the French Army, and most soldiers were concerned with nothing more than returning home, their manhood “milked.”

Unlike many other French units, however, the 179^eme Battalion Alpin de Forteresse managed to hold Fort l’Ecluse, just south of Geneva. This prevented a total encirclement of Switzerland until July 3, though the Vichy Regime was not fully installed until July 10. For that week, the Axis powers had Switzerland fully surrounded by military units. After July 10, Vichy France was no longer a potential invasion route. Hitler had, at the last minute, attempted to pass a message to the OKH negotiators demanding that the demarcation line between Germany and Vichy be moved west in order to give Germany a full encirclement of the last true neutral on the continent. Fortunately, the message did not arrive in time.

Just prior to the total French collapse, General Guisan issued Operationsbefehl Number 10, which representaed a complete overhaul of existing Swiss defensive plans. With the country now essentially surrounded, Op. Bef. 10 signaled a drastic shift in priorities. The weak state of the Swiss Army through the 1930’s rendered incapable of meaningful resistance on its own. Therefore, a secret liaison with the French General Staff had been established, which arranged for French troops to defend Swiss soil in the event of a simultaneous strike on the two countries. With France out of the picture, so were these plans.

Guisan’s concept of a Réduit national was beginning to take shape (though still within his head). In this scenario, the St. Maurice and St. Gotthard Passes in the south, plus the Fortress Sargans in the northeast, would serve as the defense line. The Alps would be their fortress.

Less easy to understand, though, was the only means by which this would function as an effective defense: 2nd, 3rd, and 4th Army Corps were to fight delaying actions at the border, while all who could would retreat to the Alpine refuge. The population centers were all located in the flat plains of the north. They would have to be left to the Germans in order for the rest to survive.

As Halbrook summarizes, for a small nation such as Switzerland “the strategy was one of dissuasion; total victory was not expected. Such a nation could not win a war with Germany, but it could promise higher losses than would be worth the cost to the aggressor.”[17] Guisan himself outlined the doctrine and its justification on July 12:

Switzerland cannot escape the threat of a direct German attack unless the German high command, while preparing such an attack, becomes convinced that a war against us would be long and expensive, would uselessly and dangerously create a new battleground in the heart of Europe, and thus would jeopardize the execution of its other plans … If we must be dragged into the struggle, we will sell our skin as dear as possible.[18]