This study addresses the application of Artificial Intelligence (AI) agents to enhance national security against Advanced Persistent Threats (APTs) in cyber warfare. With the increasing sophistication of cyber threats, particularly APTs, AI has become a critical tool for detecting, mitigating, and preventing these targeted and persistent cyberattacks. The study examines the types of AI agents applied in cybersecurity, including signature-based, anomaly-based, and autonomous systems. It also evaluates the success of AI in real-world applications, including the advantages and challenges, such as the possibility of false positives and adversarial vulnerabilities. The study further offers policy recommendations for adopting AI in national cybersecurity strategies and suggests future research directions for enhancing the resilience of AI to emerging threats. AI is generally presented as a fundamental contributor to the defense against future cyber warfare.