Since the first humans organized themselves into communities, there have been struggles for influence over others. Communities formed cities, and cities became nations, and nations, empires. But when one nation gains, another must lose, and we find ourselves looking at a world map that is constantly in a state of change.
This landscape of nations is a fluid picture over time. Empires ebb and flow, countries expand and contract and states disappear off the world stage completely. So many factors contribute to the rise and fall of nations that to attempt to explain it all would be difficult, as even the history of events and the influence they have upon the world are debatable.