 Turkey is also a member of the G20 industrial nations which brings together the 20 largest economies of the world.Turkey entered NATO in 1952 and serves as the organization's vital eastern anchor, controlling the straits leading from the Black Sea to the Mediterranean and sharing a border with Syria, Iraq, and Iran.A NATO headquarters is located in İzmir, and the United States has maintained air forces at a Turkish base called Incirlik that is located near the Mediterranean city of Adana.