The United States far and away spends the most money of any nation on “national defense”, however many critics argue that most of the resources are really used to maintain a national offense. Switzerland on the other hand has long maintained it’s neutrality yet has extremely secure borders and a strong defense from any possible invasion. According to Geoff Manaugh and Business Insider:
“To interrupt the utility of bridges, tunnels, highways, railroads, Switzerland has established three thousand points of demolition. That is the number officially printed. It has been suggested to me that to approximate a true figure a reader ought to multiply by two”
“Where a highway bridge crosses a railroad, a segment of the bridge is programmed to drop on the railroad. Primacord fuses are built into the bridge. Hidden artillery is in place on either side, set to prevent the enemy from clearing or repairing the damage.”
“Near the German border of Switzerland, every railroad and highway tunnel has been prepared to pinch shut explosively. Nearby mountains have been made so porous that whole divisions can fit inside them.”
Manaugh describes how the Alps have seen significant subterranean construction, and that Switzerland built titanic underground fortresses to withstand an attack, all hidden below sleepy villages.
In short: Switzerland is devoted to extreme neutrality. But were a nation to test that, they’re prepared to mess an invader up.