Which one is that? My own favourite one related to Liechtenstein is the vicious diplomatic war after 1991 where Liechtenstein and the Czech Republic refused to recognise each other until a few months ago (one can imagine Vaclav Havel quaking in his boots, fearful of when the Liechtensteiners will strike...)
The one where the Prince sends all seven troops out to fight in the Thirty Years' War, and they return with a friend they'd made along the way.
I also really like that one. "Why do you wear a helmet, Vaclav?" "I AM PREPARED FOR THE COMING WAR, WOMAN."
(I had an idea once, where the population of Switzerland were actually sleeper agents for an alien invasion, and the "Fortress Switzerland" mentality was actually just preparing a base for their arrival. I think the Swiss Banks were using their reputation to gather money to the alien side, so the world's economy would be crippled upon landing.)