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. == Background == 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.