Mobile Ad Hoc Networks (MANETs) have become indispensable in modern military operations; they provide decentralized, adaptive, and resilient communication frameworks in dynamic battlefield environments. This paper presents a comprehensive review of MANET innovations, challenges, and research gaps, focusing on advancements in security mechanisms, energy efficiency, routing optimization, interoperability, and AI-driven management systems. MANETs enhance military communication by enabling self-forming and self-healing networks, improving situational awareness, tactical coordination, and mission success. However, security vulnerabilities, energy constraints, and performance instability remain critical concerns that must be addressed to ensure operational resilience. Emerging technologies such as AI-powered security frameworks, blockchain authentication protocols, cognitive radio-based spectrum allocation, and energy-efficient routing strategies provide promising solutions to these challenges. The integration of autonomous optimization models, predictive analytics, and quantum cryptography further reinforces the robustness of military MANETs in contested and high-risk environments. Despite these innovations, research gaps persist, particularly in interoperability with legacy systems, cyber security frameworks, and large-scale deployment strategies. This review highlights the strategic importance of MANETs in military applications and provides insights into ongoing research aimed at enhancing their reliability and efficiency. Future advancements should prioritize intelligent, self- organizing, and cyber-secured MANET architectures, ensuring seamless communication, operational efficiency, and superior defense capabilities in next-generation warfare.