In the 21st-century geopolitical landscape, characterized by digital interconnectivity and information saturation, traditional paradigms of hard power are increasingly insufficient to explain international outcomes. This paper argues for a fundamental reconceptualization of Joseph Nye's soft power, moving beyond its origins as passive attraction to frame it as a deliberate, measurable, and strategically deployed form of strategic intelligence. By integrating interdisciplinary frameworks from political science, cognitive psychology, and data analytics, this study examines the mechanisms—identity projection, emotional resonance, algorithmic amplification, and trust engineering—through which modern influence is wielded. It further analyzes the formal and informal channels that disseminate this power, from public diplomacy to AI-curated digital environments. Crucially, the paper advances the debate by incorporating quantitative and qualitative metrics, demonstrating that soft power is not an intangible asset but a calculable one, as evidenced by global indices and digital analytics. The conclusion asserts that in an age of cognitive warfare, the nations that succeed will be those that master the science of influence, making strategic soft power a central pillar of national security and diplomatic strategy.