Industrial-age warfare has a different scale of opportunity costs associated with it than, say, agreeing to have dinner at the new Thai place down the street, to see if it is any good.
Invading someplace just to discover if it is or isn't invade-able hasn't been a workable strategy since Franciso Pizzaro tried it on Atahualpa.
> The last person to successfully invade Switzerland was... Napoleon
While I understand the idea of deterrence, your statement certainly implies the existence of unsuccessful attempts, but I don't think any attempts have even been made since.
Edit: all I am saying is that if you'd originally said "the last person to invade Switzerland ..." we wouldn't be having this exchange.
Yes, my use of the infinitive "to invade" was in the sense of the consummation of the invasive act itself; and not contingent upon the invader's assessment of the success or failure of their primary military objective, hence the adverb in the middle.
Now that we have that out of the way, IIRC there was an Austrian army mountaineering patrol on a winter training mission that got lost on the border near Liechtenstein. They ended up on a hillside in Grisons, just over the border, where a shepherd informed them that they were in the wrong country.
After some debate about proceeding further down the valley in the hope of finding a bar or restaurant, they decided that it was too cold and wet, so they marched back the way they came && called for a helicopter to pick them up.
There you go, a relatively recent but unsuccessful invasion of Switzerland.
Invading someplace just to discover if it is or isn't invade-able hasn't been a workable strategy since Franciso Pizzaro tried it on Atahualpa.