[en] This publication brings a complex and comprehensive view of the weapons of mass destruction phenomenon in the context of present military and political situation. It emphasizes the threat posed by proliferation of these destructive devices and their carriers as well as the threat present in their possession by unpredictable totalitarian regimes or terrorist groups. The publication is structured into four basic parts: Introduction Into The Topic, Nuclear Weapons, Chemical Weapons and Biological Weapons. The Introduction reflects the latest developments on the field of military technologies, which lead to the development of new destructive devices with characteristics comparable to basic types of WMDs - nuclear, chemical and biological. Based on the definition of WMD as 'weapon systems with enormous impact causing mass destruction, population, equipment and material losses', the modern mass destruction devices are assorted here, such as ecological, radiological and beam weapons, aerosol and container intelligent ammunition, the outburst of dangerous chemical substances from infrastructure, non-conventional weapons and military devices. The Nuclear Weapons part depicts the most destructive device of mass destruction mankind ever invented in close detail. It maps the history of most significant discoveries in nuclear physics, development and construction of the first nuclear weapons, accumulation of nuclear warheads and their carriers in the Cold war era, attempts of nuclear disarmament and reducing the number of nuclear weapons in possession of superpowers and their proliferation in the world's crisis regions including North Korea and Iran. The chapters devoted to theoretical grounds and physical principles of nuclear and thermonuclear weapons' functioning, the main categories and types, as well as destructive effects and consequences of use contain an adequate mathematical apparatus. This chapter's conclusion brings the overview of nuclear armament of states that officially own such weaponry and the states that are reasonably suspected to own such weaponry or try to obtain it. All the data are from open and unclassified sources published in professional periodicals and on the Internet. This chapter describes also the potential threats and consequences of terrorists' obtaining nuclear weapons. The Chemical Weapons remind that this kind of WMD has been in use since ancient history. The chemical weapons development has reached its peak in the twentieth century, along with their first mass use in combat during WW I. The next period brought the development of exceptionally efficient chemical weapons, such as the nerve-paralyzing substances. Use of chemical weapons is documented during WW II, the Vietnam War and in the Iran-Iraq War. Further chapters focus on the detailed description of individual toxic substances - nerve paralyzing, general toxic, blister, choking, physically and psychically disabling and irritating agents - their attributes, the mechanism of their effects, intoxication symptoms and possibilities of protection. Attention is paid to the process of chemical disarmament and chemical terrorism as well, stressing the threat posed by terrorists abusing dangerous industrial chemical substances present in the states' infrastructure. The next part is dedicated to the phenomenon of biological weapons nicknamed, along with chemical weapons, 'the poor man's nuclear weapon'. Given the revolutionary progress and wide availability of bio-technologies it presents the most probable weapon of mass destruction that terrorists could use to achieve their goals. The biological weapons are defined here as 'pathogenic microorganisms, the toxic products of their metabolism, certain live organisms and some synthetic substances inducing mass disease or death of humans or animals or destroying agriculture'. A short description follows of pathogenic microorganisms such as bacteria, rickettsia, viruses, molds, certain toxins that present a cross between chemical and biological weapons of mass destruction and environment substances used to destroy fores and agriculture. The biological weapons destructive requirements are defined here along with characteristics of individual diseases and properties of the most important toxins. Attention is paid to the problems of biological weapons' proliferation, efficient control as well as the risks resulting from the advances in gene engineering and biotechnology. The opportunities that biological mass destruction devices present to potential terrorists are consequently analyzed along with the possibilities of protection against attacks using biological agents. The analysis focuses on the protection in the armed forces setting and dealing with the consequences of an eventual biological attack. The conclusion deals with the questions of biological disarmament and the risks the democratic states would have. to face in case of a terrorist attack using biological weapons. (Authors)