As in the past, we can talk about the existence of interstate relations today and that these relations are becoming more and more multifaceted. It is seen that globalization has an important effect on the establishment of these versatile and new relations. It is a fact that conflicts occur at the point where interstate relations are blocked. However, it is known that the problems were tried to be solved by using different methods until the emergence of these conflicts. The first thing that comes to mind from these methods is the active use of diplomatic channels. Although the importance and methods of diplomacy as a means of reconciliation have increased, there may be situations where it is ineffective or not fully used (or not) from time to time. Despite the fact that many diplomatic studies were carried out in the Russia-Ukraine crisis, the war was inevitable. This situation can be considered extremely important in terms of demonstrating the justification of realist thought in international politics. In this study, while dealing with international politics, the importance of diplomacy, methods and theories in international politics are briefly mentioned. In addition, the idea that realist policies (against idealism) are effective in the world over the Russia-Ukraine Crisis is evaluated. In the study, the details of the Russia-Ukraine War, which kept its temperature, and the latest situation of the neo-liberal global system, which is seen as responsible for this process, have been tried to be analyzed rather than the results reflected so far.