How did Greece’s geography affect recent world events?

The question asks how Greece’s geography has affected recent world events. The term “recent world events” is rather broad, so let’s narrow it to the issue of refugees from the conflict in Syria. The fundamental elements of Greece’s geography relevant to this issue are:
1. Control over numerous small islands in the eastern Mediterranean Sea.
2. A relatively rugged, mountainous border region with both Turkey to the east and the rest of the Balkans to the north.
3. Membership in the European Union.
These three factors have conspired to make Greece the primary route through which refugees from the Syrian conflict have attempted to escape into Western Europe and seek asylum (and ultimately permanent residence) there. Many Greek islands are close enough to Syria and Turkey to make it tempting for refugees to attempt to navigate to them in various small craft. The rugged border with Turkey makes infiltration possible through that route. Finally, EU membership makes doing so attractive, because the free travel allowed among EU member states has made control of refugees problematic. Additionally, standards of living in these states are among the highest in the world, so there is a belief among refugees that “if they can just get there,” economic opportunity and freedom will be waiting. If Greece were not part of the union, this latter impetus might well not be present, as Greece itself is struggling economically and does not have a large economy which could absorb substantial numbers of refugees.
https://data2.unhcr.org/en/situations/mediterranean?id=83