NATO is a transatlantic alliance that brings North America and Europe together. One of the things that makes NATO special is its collective commitment to mutual defence. This gives it a unique strength and credibility as a deterrent against potential attackers. Until the Ukraine conflict, NATO as a security and defence alliance hardly played a role in most people's public perception. However, with the aggressor Russia and its geopolitics, we have been made aware of the importance of defense and securing freedom. With this module, we address this important actor in international security policy. Among the materials section you will find a prepared teaching unit of 45 minutes, which teachers can download and use free of charge for their upper secondary level lessons.