Chapter 2 examines how energy security and geoeconomics are reshaping global power dynamics in the twenty-first century. The war in Ukraine marked a turning point, forcing Europe to reduce dependence on Russian gas, diversify suppliers, and accelerate its energy transition. This shift has strengthened the United States’ role as a major LNG exporter and highlighted the growing importance of renewable energy technologies. Traditional energy powers, such as Russia and OPEC nations, face declining influence, while emerging players in Africa, Latin America, and Asia are gaining prominence. Energy resources remain a critical lever of geopolitical power. Russia seeks alternative markets in China and India, often at lower prices, while the EU invests in LNG infrastructure and renewables. Strategic tensions persist in regions like the Middle East and the South China Sea, as competition over hydrocarbons and rare minerals intensifies. The energy transition is central to future geopolitics, with control over critical raw materials—lithium, cobalt, and rare earths—becoming a new source of influence, particularly for China. The chapter underscores that energy security is now linked to technological, economic, and strategic autonomy. Securing supply chains, protecting infrastructure, and investing in green technologies are essential to navigate the shifting energy landscape. The likely end of the Ukraine conflict opens a new era where alliances, trade routes, and energy policies will determine the balance of global power for decades to come.