International relations as a new field of study in political science encompasses what regulates world politics and also defines the main role of different actors involved in international system. And international cooperation becomes the strategic means pooled by different actors to maintain global governance policy, where each actor can offer its participation in multilateral diplomacy in various related areas, such as economy, politics, finance, commerce, military, etc. Most often, cooperation allows different actors to work together to combat global problems that humanity and the world face at the risk of human life. Conflicts, wars, epidemics, pandemics, environmental problems, global warming, terrorist attacks, tax evasion, human trafficking, drugs, thus, all types of conflicts that threaten peace, security and stability in the world, for which negotiation remains the main diplomatic tool to facilitate good cooperation between all actors that make up the international system and in order to guarantee progress, development, peace and stability in the world. International cooperation in international relations is the subject of our study in which some key terms will be developed. First, some key theories of international cooperation will be presented, including their strengths and weaknesses, which at the same time allows us to ask: “How do these theories inform our understanding of contemporary global challenges?" Additionally, this article deepens our understanding of the impact of power dynamics in international cooperation. In this sense, we would like to emphasize how the states which are the main actors in the implementation of cooperation diplomacy seek, at the same time, to compete with each other to defend their own interests and ensure their survival in the anarchic world. To better maintain international relations and build international cooperation, the role of international organizations, whether global or regional, becomes essential to facilitate and shape global governance policy through cooperation, without neglecting the place occupied by private actors, such as NGOs. and multinational corporations. The analysis of a recent case of successful international cooperation in resolving a global issue, such as Covid-19, is what renders cooperation between different actors possible.