I think the answer is plate movement. Tectonic plate movement is the movement on the lithosphere. This movement is defined into three; we have the convergent, divergent and transform. Plate movements often caused volcanic eruptions as well as earthquakes, depending on the movement on the plates.
This is because both of these regions have specific subjective opinions about these areas which reflect their feelings and images.
What this means is that both West and East in Europe were influenced by particular political ideologies - West by democracy, whereas East was influenced by communism. Even today, Eastern and Western Europe are quite reflective of those ideologies.
The lines going up and down are longitude and the lines going from side to side are latitude.