The emergence of cyber diplomacy has redefined the dynamics of international relations, especially in times of crisis. In the context of the ongoing war between Russia and Ukraine, the digital sphere has become a critical battleground where diplomacy intersects with technology. This paper uses the literature review method to explore the case of the Russo-Ukrainian war and the cyber diplomacy operations that took place. The purpose of the paper is to draw conclusions in relation to cyber diplomacy practices in the context of contemporary international crises. The Russo-Ukrainian war highlighted the dual nature of cyber diplomacy in modern conflicts. Cyberspace tools have facilitated international solidarity, rapid information sharing and resilience building through partnerships such as NATO and EU initiatives to support Ukraine's cybersecurity and counter disinformation. However, challenges such as misinformation and fragmented communication emerged as significant risks. Russia's cyber operations, while disruptive, failed to yield decisive military or political results, revealing the complementary role of digital strategies in warfare. Public-private partnerships, particularly with technology giants, have proved vital. This case study focusing on cyber diplomacy underscores the need for balanced strategies, strong policies and enhanced global cooperation in cyber diplomacy.