Was watching a documentary a few weeks ago regarding the many bomb shelters in Switzerland, and it mentioned that during World War II all adult citizens were required to have a gun in Switzerland and citizens were trained on their use. Switzerland‘s goal was to make itself very difficult to be attacked by Germany and to ensure that all citizens were capable of fighting back. This in combination with the mountainous terrain, and the many fortifications were claimed to be a reason behind Switzerland, not being attacked by Germany. Not sure about the veracity of that though.