Since the Reformation in the 16th century, Switzerland has maintained a strong policy of armed neutrality.

An excerpt from the article 45 facts about Switzerland

In 1815, the Congress of Vienna fully restored Swiss independence, and the European powers agreed to permanently recognize Swiss neutrality. Since then, Switzerland has not fought any international war and did not join the UN until 2002. Despite this, it pursues an active foreign policy and often participates in peace processes around the world.