Diplomatic relations between countries have a long history that dates back to ancient times. In Mesopotamia, the practice of diplomacy was recorded in the 3rd century BC, in which city-states sent envoys to improve relations and resolve disputes. Over time, these relationships developed with the emergence of peace treaties and alliances. In the Middle Ages, diplomacy became more formal with the establishment of royal institutions. European countries such as France and England began sending ambassadors to represent their interests. The use of diplomatic letters and official meetings symbolized the birth of a more organized diplomatic ethic. The Industrial Revolution and developments in communications technology in the 19th century brought major reforms in diplomatic relations. The countries adopted the Vienna Convention in 1961, which standardized diplomatic protocols. This includes provisions on diplomatic immunity and the rights of ambassadors. The development of international organizations after World War II, such as the UN, added a new dimension to diplomacy. Countries are starting to collaborate to address global issues such as war, climate and health. Multilateral diplomacy is important, allowing countries to exchange views and cooperate. During the Cold War era, diplomatic relations were often overshadowed by tensions between the Western and Eastern blocs. However, meetings such as the Helsinki Summit in 1975 helped stimulate dialogue and reduce tensions. Entering the 21st century, diplomacy is increasingly influenced by digital technology. Social media and instant communications allow countries to interact more quickly. Public diplomacy has also become more prominent, where countries try to influence global public opinion. Issues such as climate change, terrorism and the migration crisis require international cooperation. Diplomacy now focuses on resolving interconnected global problems, making every agreement and collaboration between countries vital. Economic developments also have an impact on diplomatic relations. Countries are now prioritizing investment and trade, prioritizing economic diplomacy to achieve common goals. Free trade agreements are one tool in establishing closer relations. Currently, new challenges continue to emerge in the form of geopolitical uncertainty and cyber threats. Countries must adapt their diplomatic strategies to remain relevant and effective. By maintaining open dialogue and cross-border collaboration, it is hoped that diplomatic relations can continue to develop in facing the challenges of this century.