The dawn of the 21st century ushered in an era of unprecedented change in global politics. From seismic shifts in power dynamics to the rise of new social movements, each decade has introduced moments that continue to shape our world. International relations, technology, and grassroots activism have all collided to redefine how nations interact and how citizens demand change. This article explores 15 pivotal events that have not only transformed countries but also rewritten the rules of global engagement, setting the tone for our collective future.