Facial recognition technology has become a cornerstone in the fight against terrorism because it has changed the way surveillance, identification and threat identification are done. Aided by the use of artificial intelligence (AI), facial recognition technology now has the ability to search through large databases, recognize people in real time, and predict whether a person might pose a potential threat based on his or her pattern of behavior. This chapter examines the dynamic deployment of AI-based facial recognition technology in national security systems in terms of tracking down terrorist suspects, protecting critical infrastructures, and supporting rapid response time. Through biometric recognition, deep learning algorithm, and big data analytics, the accuracy and efficiency of intelligence work are improved and traditional monitoring work becomes a forward-looking and defensive fight. The chapter also analyzes the deployment of facial recognition technology by airports, in public spaces, and within urban surveillance networks and demonstrates how AI enables automatic alerting and identity checks of vast groups of people at a scale and pace not possible before. However, the chapter discusses the legal, ethical, and privacy challenges around mass surveillance, including concerns about misidentification, fraud, and bias in the database. It recommends strong regulation, international cooperation, and transparent governance in order to ensure that the use of AI facial recognition technology is compatible with human rights and fundamental freedoms. This chapter also highlights the transformative nature of AI in counterterrorism but promotes responsible, accountable, and ethically anchored technological applications.