In the context of modern defense and security operations, analysts are faced with a continuously growing set of information of different nature that causes significant information overload problems and prevents developing good situation awareness. Fortunately, Visual Analytics (VA) has emerged as an efficient way of handling and making sense of massive datasets by exploiting interactive visualization technologies and human cognitive abilities. Defence R&D Canada has conducted a review of the applicability of VA to support military and security operations. This paper is meant to provide someone new to this area with a quick overview of the current state of the art in VA. We introduce the important scientific visualization, interaction and reasoning concepts supporting VA, followed by VA advanced techniques. Then, we describe how VA can contribute to the cyber security and intelligence analysis application domains, along with promising research projects and commercial software. Finally, we discuss the future of VA research.