In the contemporary ever-evolving digital landscape, the paramount importance of fortifying national cybersecurity for safeguarding national security is unequivocal. Cybersecurity stands as a critically strategic field, demanding in-depth strategic planning. This research delves into the complexities of cybersecurity strategy, evaluation, and its myriad challenges, moving beyond conventional methodologies to illuminate this essential sector. A key contribution of our work is the creation of an innovative taxonomy that precisely classifies and categorizes strategic cybersecurity challenges, thereby enriching the discipline's lexicon and deepening the understanding of the cybersecurity environment. Additionally, this study conducts a thorough review of prevailing guidelines, models, standards, and frameworks for the assessment of cybersecurity, its maturity, and cyber power, rendering this research indispensable for decision-makers. It also methodically examines and presents a mathematical formulation for assessment indices. This provision of critical insights supports the crafting of holistic and adaptable cybersecurity strategies, promoting a robust cyber ecosystem. Consequently, nations are better positioned to adeptly manage the shifting sands of cyber threats, bolstering their global cybersecurity stature and ensuring the protection of national and international digital security interests.