Actually, Switzerland's troops accidentally crossed the border and quickly retreated after they noticed their mistake. Both countries are downplaying the incident and this story is being placed in the trivia of history pile.
The incident becomes more hilarious when one knows the history of Switzerland and
Liechtenstein. Switzerland has a serious military program but for centuries practiced neutrality. Switzerland is so neutral that it only recently joined the United Nations. Liechtenstein got rid of its military in 1868 because it cost too much and has relied on Switzerland to provide guidance in foreign affairs. With very libertarian banking laws Liechtenstein is Switzerland's Switzerland.