In recent years, the recognition of cyberspace as an emerging military domain has prompted significant changes in the approaches of countries and organizations to the concept of cyber defense. NATO, as an international military organization, has also been impacted by this process and has undertaken the task of updating and redesigning its cyber defense strategy for nearly a decade. The purpose of this article is to investigate the impact of identifying cyberspace as a new military domain on NATO's cyber defense strategy and to analyze these effects descriptively. The findings of this research indicate that recognizing cyberspace as a new military domain has significantly influenced NATO's cyber defense strategy in recent years. NATO has developed new policies and frameworks to address cyber threats and has substantially increased its investments in strengthening cyber defense capabilities. Moreover, ensuring the security of cyberspace, as a fundamental aspect of creating an effective cyber defense strategy, has played a prominent role in realizing the principle of NATO's collective defense in the cyber domain. Given the importance and necessity of updating cyber defense strategies based on current requirements and complexities in this field, the results of this research can be a valuable resource for policymakers, military commanders, and researchers active in the field of cyber defense in the Islamic Republic of Iran to make innovative decisions and develop effective strategies in this area.