Both. Greece's geographic features helped its development because of the many ports all over the country, on the mainland and the islands. Because of Greece's many ports, trade was lucrative. Goods from other countries, such as Egypt, Minor Asia, Italy, came into Greece, while at the same time Greek products and goods were exported, such as olive oil, olives, fruits, marble, etc.
On the other hand because of its geografic position, Greece was vulnerable to invasion by other near-by countries and fell prey to outside enemy forces, such as the Venetians (whose influence can still be seen today in castles in Greece), the Turks during the Ottoman empire, the Germans during WWII. Sometimes these countries occupied Greece for many years, in the case of Turkey, the occupation lasted 400 years, and during this time hundreds of Greek Orthodox churches were destroyed.
