Please answer a question about the following article about Ottoman Empire:

The economic structure of the Empire was defined by its geopolitical structure. The Ottoman Empire stood between the West and the East, thus blocking the land route eastward and forcing Spanish and Portuguese navigators to set sail in search of a new route to the Orient. The Empire controlled the spice route that Marco Polo once used. When Vasco da Gama bypassed Ottoman controlled routes and established direct trade links with India in 1498, and Christopher Columbus first journeyed to the Bahamas in 1492, the Ottoman Empire was at its zenith.

What serviced as the foundation for the structure of the economy of the Ottoman empire?
its geopolitical structure