Switzerland demonstrated its impartial standpoint during the First World War, mobilizing its armed troops only for deterrence and accepting refugees from both warring nations—refusing to take sides militarily. Staying neutral was and still is a challenging feat that was put to the ultimate test with the outbreak of World War II.

Neutrality, No Matter What

As the Third Reich aggressively expanded across Europe, the Swiss had been actively reviewing its defense and deterrence tactics considering that the main villain of the Second World War lived next door.

Even though Adolf Hitler had earlier promised that he would respect the Swiss neutral stand, after seeing how Poland, who received the same reassurance, had badly fallen into the hands of the Nazi dictator, had urged the small alpine country to reconsider its defense strategies and proceed to expand its existing fortifications just in case.

Ramping up its defense budget, Switzerland began lacing its thousands of miles of borders with explosives to deter invasion from all sides—taking advantage of its enormous, extremely rugged mountains to develop a stronghold buffer from the surrounding power-hungry Axis. Combined with its exceptional construction and engineering ingenuity, the Swiss likewise built hundreds of bunkers strategically situated near choke point routes allowing its armed forces to swiftly destroy crucial passages in the event of an attack.

The Swiss revisited its defensive plan, first developed by the government in the 1880s, dubbed the Swiss National Redoubt. It’s a comprehensive military response to foreign invasions that would allow a retreating Swiss Army a safety net using its very own rugged alps while preserving its territory. By the 1940s, they’d devised the perfect revision of the redoubt that would send a clear message to the Nazis that “Yes, they could potentially invade us, BUT at a very high cost.”

Indeed, Hitler drafted a plan, alias “Operation Tannenbaum (Fir Tree),” which detailed how German troops would attempt to capture Geneva and Lucerne while Fascist Italian Army led by Benito Mussolini would take over the Alps region. But they never pushed through with the invasion as it ended up not making any strategic sense, and, at this point in WWII, both had already lost too many resources. Invading Switzerland would mean a further dip in its deteriorating force and military equipment. Not to mention the extremely rugged terrains of the Swiss alps that would surely consume time to traverse with all the high explosives planted along the roads, the hidden bunkers and powerful tanks that invaders had to look out for, and those strategically built anti-tank blockades. It was just too impossible to pull off.

So, the Axis Powers canceled.

Switzerland successfully maintained its independence and neutrality, yet its decision to keep open trade to anyone—including the bad guys—caused controversy when the war ended.

The Swiss Way of Staying Neutral: Dig!

The Swiss military had dug more than 20,000 bunkers by the time the Axis Powers began taking over its neighboring countries—aggressively invading and subjugating most European nations, except for Switzerland.

Their creativity and resourcefulness turned their rugged landscapes into a blank canvas. They’ve constructed bunkers with powerful tanks and anti-aircraft guns so strategically placed and effectively disguised amid the alps that an unsuspecting soldier would miss them unless they had intelligence on its positions.

There were also military installations hidden beneath seemingly ordinary cabins capable of lodging battle-ready troops, as well as fake civilian houses and buildings scattered across the country equipped with machine gun turrets and other weaponry.

When the Second World War was over, the digging continued for the Swiss as the rise of the Soviet Union and the threat of nuclear destruction during the Cold War became worrisome.

This time, instead of constructing bunkers in the Alps, the Swiss began incorporating air-tight fallout shelters into existing civilian homes, including apartment complexes and public infrastructures such as schools, hospitals, etc., across the country. Accessibility to these bunkers also became a federal policy executed and regulated by cantons (a Swiss political subdivision), ensuring optimum security and protection for its entire population—leaving no Swiss citizen behind.

“Every person in the country must have a spot in a bunker in case of some kind of catastrophe,” quoted from swissinfo.ch.

Between the 1960s and 1970s, the Swiss built more than 300,000 private and public shelters, more than enough to house the entire population, plus a healthy surplus. These underground refuges were mostly made with formidable concrete sealed in enormously thick doors capable of withstanding powerful blasts and blocking away the effect of modern warfare weapons like nuclear, biological, and chemical weapons.

These shelters were regulated to self-sustain themselves with water and energy, as well as mandated to feature air filtration systems, basic facilities such as bathrooms and bedrooms, and must store food and water enough for at least five days. More prominent bunkers have a hospital, canteen, and dormitories big enough to cater to at least 200 people.

It should be noted, though, that while safety has been a major priority when building these safe havens, privacy is surely not guaranteed and may create potential living issues when conflict or after-effects of, say, nuclear war will last for months on end.

Nevertheless, the digging and building of bunkers have become so prominent that they blended into the Swiss identity.

Reviving Its Most Effective Deterrence

Two major conflicts came and went, and while Switzerland evolved with the changing times, its neutrality remained constant. Nonetheless, as no immediate threat occurred in Europe, the Swiss government began seeing no imperative need to maintain these fortifications and bunkers, which cost a lot of maintenance.

The explosives installed around its borders and vital bridges and roads were gradually dismantled, and by 2014, Switzerland had unequipped itself with the deterrence tactic that saved itself from being invaded.

Bunkers in the woods and up in the alps were abandoned. Some were acquired by private companies and owners, who converted these shelters into cozy hotels, cheese cellars, and, recently, information technology companies running data server services. Meanwhile, residential homes with fallout shelters on their basements utilized the now spare room as home cellars, storage, or can be anything really—just with a heavy steel door.

Several individuals procured these underground tunnels and continued to maintain them as is, living on or near them as caretakers, while the rest sit mostly abandoned, which avid hikers and adventurers occasionally try to find—challenging themselves to see how many they can recognize or spot while exploring the Swiss alps.

However, as the world shifts and becomes more volatile again, with the threat of nuclear war becoming more real, the Swiss are again reconsidering its decade-long defense and deterrence tactics.

Russia’s invasion of Ukraine has sparked discussions on whether bunkers should be regarded again in reassessing the country’s defense and security. Many homeowners and building owners were also scrambling to call for contractors to schedule inspection and maintenance over their bomb shelters, ensuring it is fit for survival in case of nuclear fallout. Before, these contractors specializing in bunkers had little to no inquiries. But now their phone lines were almost always busy.

“Before, the shelter [were] not very much in focus for our population. But with the crisis [in] Ukraine, we got a lot of phone calls. A lot of people were very anxious and wanted to know where they can go to in case of incident,” said Andrea Lee, the deputy head of the civil protection department for the canton, in an interview with CGTN last May.

One nuclear fallout shelter being widely discussed in the aftermath of the Ukrainian war is the Sonnenberg bunker, known as the largest facility of its kind with a capacity of about 20,000. Built from 1971 to 1976, the facility is located about one kilometer west of Lucerne train station. It has a seven-story cavern located over the A2 highway, which transports at least 55,000 vehicles every day.

As a Cold War fan, there's something I'm really looking forward to. Swiss law dictates that every citizen has access to a nuclear bunker. Consequently, many buildings have one in the cellar. There are 300k private + 5k public shelters. One, Sonnenberg, can house 200k people. pic.twitter.com/DBrF3yi7Tq

— Richard Littler (@richard_littler) February 6, 2018

In the event of a conflict, however, this cavern turns into a headquarters for civil defense personnel, with each of its seven floors working on its own role, from energy and ventilation to beds and toilets that would accommodate thousands of refugees. It is said to be able to withstand a one-megaton nuclear blast at least from one kilometer away, with its blast door thickness measuring 1.5 meters, and weighs about 350 tons (317,515 kg).

According to local tour guides, despite being built in WWII and spending the last decade abandoned, these bunkers stay well-capable of operating as safe fortresses with a few modern upgrades.

The times have clearly changed, and while Switzerland is increasingly participating in the international community, assisting humanitarian projects, it remains fiercely impartial in military matters.

Nonetheless, the question now is whether, if present global tensions escalate into all-out war, God forbid, will the Swiss maintain their century-long commitment to neutrality and stay hidden underneath their strongholds, or will they select which side to support?

We probably shouldn’t hope to figure that one out.

If you’re curious to see more about what’s inside one of these bunkers, you can check out the below.