Purpose: to present the national security environment from the perspective of the main assumptions formulated by Aristotle. This was he, who examined 158 constitutions of states, and he also undertook the work of describing the known regimes in detail. He can be considered the first thinker to approach the entire spectrum of political and social issues in a scientific manner. Method: the research was conducted using the following general scientific and special methods: the historical method during the study of the examination of constitutions by Aristotle; the method of analysis and synthesis related to the functioning of the state by Aristotle, abstract-logical method – for formulating theoretical generalizations and research conclusions. The results of the study: are related to Aristotleʼs indications, that a democratic system can be a matrix for other forms of government and of utmost importance is to preserve sustainability. The intention was not to develop or to reject the existing theories, but it was possible to formulate the assumption, that democracy, as we know it, has been a specific system whose durability depends on specific virtues and goods, most often called liberal. Theoretical implications: the practitioners can learn from the paper, that following Aristotle, the virtue of moderation should be incorporated into the cross-section of liberal political values for the benefit of the sustainability of democracy and the citizens who participate in its achievements. In this respect, the relationship between politics and ethics was revealed, which is characteristic of the classically understood philosophy of politics. Practical implications: the findings could serve as the research streams related to deeper analysis of the democratic systems, and the relations with the essence of the democracy of ancient Athens and looking for inspiration and parallel solutions for the political culture of current liberal democratic societies. Papertype: theoretical.