Over the past few decades, the field of counterintelligence has become increasingly accessible to lay and professional public; this is the result of many factors, such as the opening of state archives, the declassification of secret documents, materials and literature pertaining to intelligence, counterintelligence, and security services, initiatives for improved oversight, democratization of society and political systems, human curiosity, and especially the need for a new paradigm of counterintelligence. When faced with the question of how to proceed, we encounter the following problem: there are numerous understandings, definitions, and practices of counterintelligence across the world. The European region is also pressed with the necessity of finding a new counterintelligence paradigm and often looks for answers to American literature because it is the most publicly accessible. We wish to emphasize, however, that there is a specifically European perspective on counterintelligence, which is not adequately covered in literature. There are some minor but also fundamental differences between the European and American perspectives, so that the ‘general’ concept of counterintelligence, which is mostly based on US literature, should also be examined form a European perspective; this is important for European and non- European countries alike. A partial European perspective on (primarily) the theory of counterintelligence is presented; it is based on the Balkans, since the regional counterintelligence was heavily influenced by other European services and thus reflects a European counterintelligence viewpoint. At the same time, the Balkan states possess a more complex view of counterintelligence, which is not well known in the world.

The comparative analysis of American and European literature has revealed the main reasons for the differences in the understanding of counterintelligence; these are the result of varieties in linguistic use, the different interpretations of the expression counterintelligence, and the grouping of various activities under a single umbrella activity and service due to similar methods of work, identical or common threats, and similar goals. The wealth of available literature demonstrates that counterintelligence has been given increasing research attention; however, there is no consensus regarding the definition of counterintelligence. This is further reflected in practice, which then feeds back into the theoretical development of counterintelligence. To remedy this, we propose a new definition of counterintelligence, which was shaped on the basis of analyzed literature and therefore stems from theory rather than practice. On the basis of definition, we have come up with two representations: 1) representation of the counterintelligence process; 2) representation of the counterintelligence process operating against foreign intelligence activity. These two representations illustrate the working of counterintelligence and counterintelligence services in practice; they are based on the proposed definition and the idea that counterintelligence is aimed at foreign intelligence activity and processes but not at foreign security and other security threats, which are not the result of intelligence activities. The chapter concludes with the description of some unwritten counterintelligence principles, which are part of counterintelligence subculture.

Even though the greater part of intelligence has moved into virtual space, this is not the case with counterintelligence: its essential, core part still remains moored in the real world. Modern technology cannot replace people, especially not in counterintelligence, which is why fundamental counterintelligence methods are rooted in people and human activity. Today's counterintelligence methods and methodics are similar and even identical to those from the past, except that they have adapted to technological advances and societal changes; the methodology of counterintelligence, however, remains unchanged. Some fundamental counterintelligence methods are examined, which have not significantly changed through history—we are referring to the use of double combination and the process of handling double agents, moles, defectors, covert surveillance of people, things, and facilities, denial, deception, counterintelligence protection, counter-surveillance, counter-denial, and counterdeception.

The chapter is dedicated to human resources in the field of counterintelligence. Whereas, technological developments have brought about progress in intelligence, counterintelligence, and security, the human element has remained unchanged since the very beginning and remains key part of counterintelligence. The section presents some of the main characteristics of counterintelligence operatives, especially in relation to what shaped them and why. It is important to fully understand these circumstances and reasons, since anyone can, knowingly or unknowingly, become the target of foreign intelligence activity, e.g. a secret agent, an intermediary, or bait; the text looks at factors that influence whether a person is of interest to a foreign service. People of interest to foreign services often become secret agents, which is why it is important for counterintelligence services to be aware of the indicators that may alert them to foreign agents and to be familiar with the most common groups of people recruited as secret agents. Such knowledge should also be vital to state officials as well as people in the industry (especially in high tech, energetics, telecommunications, etc.), since it can contribute to a timely detection of spies. Operatives are trained in concealing their identities and covering their tracks, so they are more difficult to uncover than agents. A special form of operative is discussed, i.e. an operative working under the guise of a diplomat.

The chapter presents contemporary issues worthy of more detailed attention in theory and especially in practice of counterintelligence. The first dilemma concerns the question of ethics in counterintelligence, which has long been a source of contention among lawyers, sociologists, philosophers, and practicians in the field of security. The text furthermore highlights the problem of ‘grey zone’ in counterintelligence and explains why ethical counterintelligence is an oxymoron; it confronts the reader with the ethical dilemma of the relative importance of national security vs. individual’s human rights. A slightly less known modern issue is the question of OSINT and its legality; foreign intelligence services can use OSINT to extend from ostensibly legal into half-legal or illegal fields of activity and thus avoid counterintelligence surveillance and the activities of other services. The last issue presented is the question of trust among partner state services; in 2015 we witnessed the disclosure of documents revealing the extent of NSA surveillance of leaders, ministers, and state body officials from Germany, France, Brazil and Japan. These revelations sparked a debate on the acceptability of spying on ‘friendly’ or partner states; in itself this is not a new dilemma, however it was previously unknown to the public.

Vladimir Vauhnik, first colonel and then brigadier general in the army of Kingdom of Yugoslavia, is an important and yet almost forgotten figure of the Second World War; his efforts might have changed the course of the war for the better. Prior to and during the Second World War, Vauhnik was Yugoslavia’s military attaché to Berlin, where he spied on Germans. He used covert and legal methods to obtain information on the basis of which he was probably the first in the world to determine that Nazi Germany would invade Poland, and later, the Kingdom of Yugoslavia and the Soviet Union. The chapter presents a section from Vauhnik’s autobiography, in particular the difficulties caused by Vauhnik’s intelligence and counterintelligence activities to the German counterintelligence and the Gestapo, which was run by Vauhnik’s ‘nemesis’, Walter Schellenberg. Vauhnik was successful in evading the Germans, but was eventually put under surveillance and then arrested together with other Yugoslav intelligence operatives in Germany and occupied territories, following Hitler’s orders.