7 countries that have never been invaded by an outside army

Japan's insular position and formidable natural barriers have historically deterred invasions. Despite facing numerous threats, including Mongol invasions in the 13th century, Japan's military prowess and geographical advantages have kept foreign armies at bay.

Thailand stands as the only Southeast Asian nation never colonized by a European power. Through astute diplomacy and strategic concessions, Thailand preserved its sovereignty during the colonial era.

Founded by freed American slaves in the 19th century, Liberia maintained a policy of neutrality and avoided colonial domination. Its unique status and diplomatic efforts helped it remain unscathed during the colonial period.

Bhutan's rugged terrain and strategic diplomacy have shielded it from foreign invasions. While it faced internal conflicts and border disputes, Bhutan's isolation and cautious foreign policy have preserved its independence.

As one of the world's oldest republics, San Marino has maintained a policy of neutrality and non-interference. Its small size and diplomatic relations have allowed it to avoid foreign invasions throughout its history.

The Vatican, as the spiritual and administrative center of the Roman Catholic Church, has remained neutral in international conflicts. Its unique status and diplomatic efforts have kept it free from foreign military incursions.

Liechtenstein's policy of neutrality and lack of a standing army have contributed to its avoidance of foreign invasions. Its strategic location and diplomatic relations have helped maintain its sovereignty.