Switzerland's avoidance of invasion during the Second World War was influenced by a combination of strategic, geographic, and economic factors, according to historians analyzing the period. While neutrality alone did not guarantee safety—several other neutral countries, including Norway, Belgium, and the Netherlands, were invaded by Nazi Germany—Switzerland's unique circumstances made an incursion less appealing to the German military.

The country's mountainous terrain played a significant role in deterring an invasion. Switzerland is characterized by rugged mountain ranges, narrow valleys, and a limited number of vital transport routes. Such geography posed considerable logistical challenges for any invading force. The Swiss military capitalized on these natural defenses through its National Redoubt strategy, which involved an organized withdrawal of forces into heavily fortified Alpine positions if an invasion occurred. From these strongholds, Swiss troops would have continued resistance, employing tactics such as destroying critical infrastructure—including tunnels, bridges, and railways—to hinder enemy movement and supply lines.

While Germany might have been able to occupy Switzerland’s low-lying areas relatively easily, securing control of the strategically essential Alpine passes and transportation networks would have required significant resources and risk. This potential for prolonged conflict in difficult terrain likely weighed heavily in German strategic calculations.

Economic considerations also factored into Germany's decision to refrain from invasion. Switzerland maintained extensive financial and commercial links with the German war effort. Swiss banks facilitated financial transactions, and Swiss manufacturers and trade networks served as intermediaries, enabling Germany to access vital resources without direct control over Swiss territory. This arrangement provided Berlin with economic benefits while avoiding the expenses and uncertainties associated with military occupation.

Consequently, the combination of formidable natural defenses, a well-prepared military strategy, and Switzerland's economic utility reduced the incentive for Germany to launch a full-scale invasion during the conflict.