Geology makes a profound contribution to stimulating harmony among nations and cultures through addressing shared challenges and opportunities. This paper explores the intersection of geology and international cooperation, highlighting the importance of collaborative approaches to managing shared resources, mitigating natural hazards, and promoting sustainable development. Transboundary water resources, such as the Nile and Mekong River Basins, require cooperative management to ensure equitable distribution and sustainable use. Mineral diplomacy can help secure access to critical minerals and metals, while reducing the risk of conflict. Earthquake and tsunami early warning systems demonstrate the potential for geoscience to save lives and reduce disaster impact. Climate change adaptation and resilience require international cooperation, innovative technologies, and community-based initiatives. Environmental conservation and sustainability rely on protecting shared ecosystems, promoting sustainable development, and leveraging science diplomacy. Geoscience research collaborations, earth observation, and monitoring are essential for addressing global challenges and promoting peaceful relations among nations. By identifying the critical purpose of geology within international cooperation, we can promote more collaboration, mutual understanding, and peaceful resolution of conflicts, ultimately contributing to a more harmonious world.