The proposed book examines events related to two opposing trends in international politics in the 1920s and 1930s. The essence of the first is that after the Great War of 1914-1918. the governments of the Entente countries seriously dreamed of a Great Peace. Having emerged victorious from the monstrous massacre, disarming their former opponents, they believed that in the future they would be able to resolve disputes among themselves through negotiations. Therefore, they created the League of Nations, went to serious quantitative and qualitative restrictions on their land, air and naval forces. The essence of the second trend boiled down to the fact that, contrary to the good intentions of the leadership of the great powers, over twenty years in the world there have been over thirty military conflicts and local wars. The building of the international world order was persistently set on fire from different sides. In the end, a fire broke out in a new worldwide massacre, even larger and more brutal than the first. Both of these trends are discussed in detail in this book on the basis of facts related to the development and application of the naval fleets of great and minor naval powers.