Switzerland is a neutral country. There is a quite simple reason why Switzerland has never been invaded ...

The day before yesterday at precisely 13:30 Alarms went off across the whole of Switzerland, just to remind us just what we would hear, if someone actually did press The Red Button.
By chance I heard about the tests on the morning news. Therefore, when the alarms went off, I was able - along with my Swiss colleagues - to pretend that nothing was happening. See Mind over matter.

On my way home yesterday evening, I encountered a large group of armed men dressed in jeans and anoraks and armed to the teeth with Assault rifles and submachine guns. After the initial shock, I realised, that they were members of the Swiss Army on their way to shooting practice.

Military service for Swiss males is obligatory. At the age of about 20, every Swiss male goes through 118 consecutive days of recruit training in the Rekrutenschule. By the Federal Constitution of 1874, military servicemen are given their first equipment, clothing and arms. After the first training period, conscripts must keep gun, ammunition and equipment an ihrem Wohnort ("in their homes") until the end of their term of service.
Enlisted men are issued a SIg 550 automatic assault rifle and officers a semi-automatic pistol, Each reservist is issued 50 rounds of ammunition in sealed packs for emergency use.
Crimes, committed with army guns and ammunition, are almost non-existent - after all, it is against the law to crack open the boxes of ammunition!

Over a soldier's career he also spends scattered days on mandatory equipment inspections and required target practice. Thus, in a 30-year mandatory military career, a Swiss man only spends about one year in direct military service. Following discharge from the regular army, men serve on reserve status until the age of 50 (55 for officers).
After discharge from service, the man is given an assault gun free from registration or obligation. Officers carry pistols rather than rifles and are given their pistols at the end of their service. When the government adopts a new infantry rifle, it sells the old ones to the public.

it might be noted that there are about 420,000 assault rifles stored at private homes, mostly SIG 550 types. Additionally, there are some 320,000 assault rifles and military pistols exempted from military service in private possession, all selective-fire weapons having been converted to semi-automatic operation only. In addition, there are several hundred thousand other semi-automatic small arms classified as carbines. The total number of firearms in private homes is estimated minimally at 1.2 million; more liberal estimates put the number at 3 million.

I have heard it said, that no army in the world can be mobilised as fast as the Swiss Army. I presume, that when the alarm goes off in earnest, they run down to the cellar, jump into their uniform, grab their assault gun and jump on the next bus for the front.

The Swiss do not have an army, they are the army, says one government publication. Fully deployed, the Swiss army has 15.2 men per square kilometre; in contrast, the U.S.A. and U.S.S.R. have only .2 soldiers per square kilometre. Switzerland is 76 times denser with soldiers than either superpower. Indeed, only Israel has more army per square kilometre.

In 1847-48, liberals throughout Europe revolted against aristocratic rule. Only in Switzerland did they succeed, taking control of the whole nation following a brief conflict called the Sonderbrund War. (Total casualties were only 128.) Civil rights were firmly guaranteed, and all vestiges of feudalism were abolished.
Despite the hopes of German reformers, the Swiss did not send their people's army into Germany in 1848 to assist popular revolution there. When the German revolution failed, autocratic Prussia considered invading Switzerland, but decided the task was impossible.

During World War I, both France and Germany considered invading Switzerland to attack each other's flank. In World War II, Hitler wanted the Swiss gold reserves and needed free communications and transit through Switzerland to supply Axis forces in the Mediterranean. But when military planners looked at Switzerland's well-armed citizenry, mountainous terrain, and civil defence fortifications, Switzerland lost its appeal as an invasion target. While two World Wars raged, Switzerland enjoyed a secure peace.

Switzerland is also the only Western nation to provide shelters fully stocked with food and enough supplies to last a year for all its citizens in case of war. The banks and supermarkets subsidise much of the stockpiling. The banks also have plans to move their gold into the mountainous center of Switzerland in case of invasion.
Every new home that is built, is required to devote an extensive potion of its cellar to provision of shelter.
A number of Swiss citizens I know are not really happy about this 'waste of space'.
I recently looked into the shelter at the house of friends - it was full of bikes and the geraniums spend the winter there.
Uuhm ...
... this just happens to be against the law.
What will they do if someone really presses The Red Button?

Reference: The Swiss And Their Guns; David B. Kopel/Wikipedia.