This article deals with the question «Why did the First World War start?» Here will be discussed such topics as geopolitical interests of the countries which were involved in the war, international relations, the events which make the countries start the conflict, the preparation for it and international crises before the tragedy. The article deals with the policy of such countries as Serbia, Austria-Hungary, Germany, Russia, Great Britain and France. The reader will also find information about the assassination in Sarajevo, its influence on the war. World War I became the prologue to the 20th century. Without any doubt, it could be described as turning point in the history. It is impossible to understand the events of the 20th century which are discussive nowadays without the knowledge of World War I reasons. It led to the collapse of 4 empires, the creation of many new states including the USSR which was a unique one for that time, the situation where winners of the war should have built new system of international relations, but they did not succeed. New political movements appear which were ruinous for the peace; a war became more violent since then. War and ultimatums still exist in the world as tools of foreign policy. For example, not far from now D. Trump has been about to start a war with Iran which is one of the most important political powers in the Middle East or Ukraine supported by NATO have been acting aggressively for a long time. It could lead to a new global conflict with many victims of it or even to the extinction of the humankind. Modern people should remember about the consequences and try to prevent a new big war. If the actors of the international relations understand the reasons of World War I, they can avoid that traps and prevent new tragedy.

This essay aims at defining the "white spots" in the conception of the growing totalisation and industrialisation of warfare in the first half of the century. The author tries to explore the events and circumstances which fall out of the idea that there was a direct link between WWI and WWII, defended by some scholars, who prefer to speak about the "Second Thirty Years' War" of 1914 – 1945. The article does not seek to debunk the conception of the warfare totalisation, but to precise the field of its application and to outline the ways of its further development. Firstly, the author analyses the inner factors which limited the totalisation process; secondly, he explores the events which did not match precisely the total war conception; finally, he gives his opinion about the lines to improve and to enrich the set of ideas about the war evolution in the first half of the 20th century.
The main conclusions of the essay are as follows. The definition of a military conflict as "total" could be an instrument of its analysis; nevertheless, the situation could be the opposite one. The "totality" of the conflict itself often should be the object of the explanation, being the result of the many different factors, the constellation of the unique circumstances, as it happens not infrequently in the human history. The idea of the growing totalisation and industrialisation of warfare as the trunk line of the military evolution in the first half of the 20th century does not cover the whole range of the historical events in their diversity. The factors which stimulated the totalisation of warfare (states, technologies, and ideologies) in the same time put the inner limits on this process, preventing it from becoming absolute. The "total war" conception also leaves aside some important circumstances, which influenced the military conflicts and doctrine in 1914 – 1945, eg., the role of the "human factor", the specific operative and strategic environment of a conflict, the significance of the colonial and "small" wars of the interwar period. Nevertheless, this conception continues to be a valuable research instrument, especially, if it is enriched with the ideas taken from social and economic history and the "world system" theory.

This paper examines the causes of the Russo-Japanese War of 1904–1905, the conflict that affected the historical fate of both Russia and Japan. The relevance of the research is that there are still contradictions between Russia and Japan, the conflict of interests related to the ownership of the Kuril Islands. The purpose of the paper is to study the causes of the Russo-Japanese War of 1904-1905 in order to empirically test some of the provisions of classical political realism with the help of its theoretical toolkit. In the author’s opinion, such analysis allows one to focus on the most important things in order to answer why it was not possible to solve the conflicts between Russia and Japan and avoid the war. To achieve the goal, the author sets several research tasks, among which he emphasizes comprehension of the theoretical heritage of classical political realism in the context of the Russo-Japanese war, application of the provisions of this theoretical paradigm to the historical events preceding the war, study of the immediate causes
of the conflict. In his article, the author uses both the works by classical political realists and a vast bibliography of the the Russian- Japanese war of 1904-1905. The article examines the international situation in Asia, the relationship of countries in this region, their interests, on the basis of which one or another subject’s behavior can be explained. In the study, the author
leads to the conclusion that the war was made possible for several reasons:
imperialism; force, as the main indicator, and the consequent power politics; the use of contradictions between countries for their own purposes; uncompromising adherence to national interests.