Achievement of strategy objectives of defensive organizations is in close connection with the use of an adequate technology. This paper explains why augmented reality, technology that superimposes digital information over real world information, requires special attention in defense industry. The authors identified and described several key roles of AR in defensive activities: real situations with special focus on critical situations, trainings, real-time remote collaboration, maintenance, repair, and overhaul, as well as security system checks. Some challenges of using AR in defensive activities are outlined, and hints for future researches of this increasingly important technology are given.