The time Switzerland accidentally invaded Liechtenstein
In March 2007, a company of 170 Swiss infantry soldiers accidentally crossed the unmarked border into neighboring Liechtenstein during a nighttime military training exercise. Armed with assault rifles but no ammunition, the soldiers marched over a mile into the tiny principality before realizing their mistake and turning back. Liechtenstein's government only found out about the "invasion" when Switzerland officially apologized the next morning.
A Wrong Turn in the Dark
In March 2007, a company of 170 Swiss military recruits set out into the forested, mountainous terrain near the eastern edge of Switzerland for a standard nighttime navigation exercise. The soldiers carried their standard-issue assault rifles, though the weapons were completely unloaded in accordance with routine training protocol. The weather conditions during the drill were poor, with heavy cloud cover and darkness obscuring the surrounding landscape. Navigating through rough terrain on foot, the unit followed what they believed to be their assigned training route.
Without realizing it, the entire formation crossed the international frontier into the neighboring Principality of Liechtenstein. Because the border between the two countries contains no fences, walls, or manned checkpoints, there was no physical barrier or signpost to alert the commanders that they had left Swiss territory. The troops marched more than a kilometer into Liechtenstein before someone finally checked the coordinates, realized the unit was in the wrong country, and ordered an immediate turnaround back across the border.
The Apology Before the Discovery
The most unusual aspect of the cross-border incursion was that the government and residents of Liechtenstein were completely unaware it had occurred. The Swiss soldiers had walked through an unpopulated wooded area under the cover of night, without causing any disturbance or property damage. Life in the tiny principality continued entirely uninterrupted, and local authorities received no reports of armed foreign troops on domestic soil.
Liechtenstein's officials only learned of the incident the following morning, when the Swiss military formally contacted them to report the mistake and deliver an official diplomatic apology. The Liechtenstein government accepted the apology with good humor, acknowledging that these things happen in rugged mountain terrain. Representatives from Liechtenstein's Ministry of the Interior publicly noted that the event was hardly an invasion and pointed out that no one in the country had even noticed the brief presence of the Swiss troops.
An Invisible Border and a Deep Partnership
To understand how 170 armed soldiers could wander into another sovereign state unnoticed, one must understand the unique relationship between Switzerland and Liechtenstein. The border between the two nations spans roughly forty-one kilometers, much of it defined by the Rhine River and steep Alpine ridges. For over a century, this boundary has functioned as an open border, lacking border guards or customs gates due to an extraordinarily deep bilateral partnership.
Following the economic collapse of Austria-Hungary after the First World War, Liechtenstein turned toward Switzerland for economic and administrative alignment. In 1923, the two states signed a customs union treaty that integrated Liechtenstein into the Swiss customs territory. The principality also adopted the Swiss franc as its official currency. Today, Swiss border guards police Liechtenstein's external frontier with Austria, and Switzerland represents Liechtenstein diplomatically in countries where the principality does not maintain its own embassy.
A History of Alpine Military Mishaps
The 2007 border crossing was not the first time the Swiss military inadvertently intruded into Liechtenstein. Decades of training exercises in the confined valleys near the border have occasionally led to bizarre cross-border accidents. In 1968, Swiss artillery units conducting target practice accidentally fired five shells across the border into Liechtenstein, striking near the ski resort area of Malbun and damaging some property, for which Switzerland promptly paid compensation.
Similar incidents occurred in subsequent decades due to the challenging Alpine geography. In 1985, during a high-altitude exercise conducted during severe winds, Swiss anti-aircraft rockets were blown off course and ignited a sizable forest fire in the protected Bannwald forest above the Liechtenstein village of Balzers. Switzerland once again compensated the principality for the environmental damage. Later, in 1992, Swiss army recruits on an exercise mistook their map coordinates and established an observation post inside Liechtenstein territory, withdrawing as soon as the error was discovered.
Defense Without an Army
The complete lack of alarm during these border incursions also stems from Liechtenstein's unique defense status. The principality has not maintained a standing army of its own since 1868, when the military was dissolved due to the high cost of maintenance following the Austro-Prussian War. The constitution allows for the re-establishment of an armed force in times of national crisis, but the country has relied entirely on a small national police force for domestic law enforcement for more than a century and a half.
Although Switzerland does not have a formal, binding mutual defense treaty requiring it to protect Liechtenstein in the event of an attack, the two countries maintain an implicit security understanding. Swiss authorities provide search-and-rescue capabilities, disaster relief, and emergency coordination services when necessary. Because Liechtenstein views Switzerland as its closest diplomatic and economic ally, accidental military incursions are viewed as benign training errors rather than threats to national sovereignty.
Why Geography Shapes Border Blunders
The repeated navigational blunders highlight the sheer physical complexity of maneuvering military units through the Alps. High mountain ridges, dense forests, and sudden changes in weather can easily disorient troops operating at night, even with modern navigational tools. When sovereign borders follow natural ridgelines rather than artificial barriers, human error can quickly lead to an unintended crossing from one country into another.
In the end, the 2007 incident remains an emblematic example of Swiss-Liechtenstein relations. In a world where cross-border military movements typically signal severe diplomatic crises, the open border and mutual trust between these two Alpine neighbors turned an accidental foreign invasion into an amusing diplomatic footnote that concluded with a simple phone call and a handshake.
Key takeaways
•In March 2007, 170 armed Swiss soldiers accidentally marched over a kilometer into Liechtenstein during a nighttime training exercise in poor weather.
•Liechtenstein authorities were completely unaware of the incursion until Swiss officials called the next morning to apologize.
•The open border is a result of a 1923 customs treaty, with Liechtenstein using the Swiss franc and sharing deeply integrated administrative ties with Switzerland.
•Liechtenstein has had no standing army since 1868, and previous Swiss military mishaps in the area include stray artillery shells and rocket-induced forest fires.