The effective Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR) systems are crucial for modern military operations providing clear situational awareness and vital elements for decision-making. Various AI techniques have been already applied to enhance data integration and some other C4ISR components. This article proposes to explore the potential of Large Language Models (LLMs) to enhance the current C4ISR capacities such as analyzing vast amounts of data, translating languages, and generating diverse creative text formats that make them useful for heterogeneous data and information fusion, threats and fakes detection and analysis and decision support. After the introduction, the literature review discusses the technical considerations and potential benefits from the integration of LLMs into C4ISR systems. This discussion includes the functionalities such as multisource and multimodal data integration, detection, analysis and prediction of threats and misinformation, decision support through analysis of complex scenarios, identifying potential courses of action, and providing real-time recommendations to commanders working in evolving situations. The main challenges related to the use of today’s LLMs to enhance C4ISR framework such as data security, model interpretability, and bias mitigation will be studied during this research. The specific challenges will be derived from the main case study. This article includes also some characteristics that may serve to elaborate the best-suited framework. This article ends by perspective for future work.