The 12-Day War between Iran and Israel, as one of the first manifestations of the loss of cohesion within the Axis of Resistance following the fall of Bashar al-Assad’s regime, subjected not only regional equations but also the deterrence conditions of the opposing parties to a severe test. However, identifying the roots of these deficiencies in the deterrence domain of the Islamic Republic of Iran from an Iranian perspective, and offering proposed solutions to restore and strengthen it, is a concern that gives rise to the following question: What shortcomings has the Islamic Republic of Iran exhibited in fifth-generation warfare that, especially after the 12-Day War, have undermined its strategic resilience and deterrence? In response, this article argues that warfare in the fifth generation—coinciding with the age of complexity-chaos in international relations—has undergone dramatic transformations. Consequently, the methods of controlling such conflicts must also inevitably undergo change and transformation. To this end, the Islamic Republic of Iran needs to alter its perspective on the control of conflicts and new wars and adopt a hybrid approach to deterrence in hybrid wars. This hypothesis will be examined using abduction within the framework of Complexity-Chaos Theory and Network Theory, and solutions will be proposed in four domains—geopolitical, geo-economic, geo-cultural, and geo-cyber—in order to restore and strengthen the deterrence of the Islamic Republic of Iran.