The paper deals with the key impacts of the results of the Second World War on the new geopolitical organization of the world and their changes in the international system and international relations. The main aim in this context is to outline the initial situation and subsequent changes as a result of World War II. The monitored changes will concern Europe, Africa, America and Asia, as well as changes and practice of diplomacy in the context of the monitored events. A description and analysis will be used to reflect the topic, following the above factors. The article mainly uses Czech and foreign sources that deal with the researched issue.