History of Switzerland
Switzerland's most important exports during the war were precision machine tools, watches, jewel bearings (used in bombsights), electricity, and dairy products. During World War Two, the Swiss franc was the only remaining major freely convertible currency in the world, and both the Allies and the Germans sold large amounts of gold to the Swiss National Bank. Between 1940 and 1945, the German Reichsbank sold 1.3 billion francs worth of gold to Swiss Banks in exchange for Swiss francs and other foreign currency.
Liechtenstein–Switzerland relations
At the request of Liechtenstein's government in 1919, Switzerland safeguards Liechtenstein's interests and citizens abroad. The two form a common economic and monetary area (Liechtenstein has used the Swiss franc (since 1920) and has had a customs union (since 1924) with Switzerland with open borders (though both are now also party to the Schengen Agreement). The countries also have a common patent system. Switzerland is empowered to enter into treaties on Liechtenstein's behalf if Liechtenstein is not represented at the treaty negotiations; this power has most often been exercised with treaties involving customs duties or procedures.