Jordan lies in the heart of the Middle East in an area known as the Levant, surrounded by Israel, Syria, Iraq, Saudi Arabia and the Red Sea. Rather than being determined by discrete topographical features, Jordan's northern, eastern and southern borders are the result of early 20th century imperial politics. The core of the country is the northern portion of the Jordan Valley and the adjacent highland plateaus, where most of Jordan's nearly 10 million inhabitants reside. Jordan's three biggest cities, Amman, Irbid and Zarqa, are all located in this area. The fertile east bank of the Jordan River is responsible for most of Amman's agricultural production. Most of the rest of the country is desert, containing portions of both the Syrian and Northern Arabian Deserts. Jordan's two primary geographic challenges are its lack of natural resources and its diverse population. For domestic energy needs, Jordan depends on imported oil and natural gas, though it is a significant exporter of phosphates, potash and fertilizers. Native Jordanians are descendants of the Bedouin tribes historically from the region, but over half of Jordan's population is made up of Palestinian Arabs, a reflection of Jordan's shared border and deep historic ties with the Palestinian Territories. Hundreds of thousands of Syrian and Iraqi refugees also live in the country, as well as pockets of Circassians, Armenians and Assyrians. Despite its artificial borders, dearth of natural resources and proximity to regional conflicts in Iraq, Syria and the Palestinian Territories, Jordan has been relatively stable since its founding in 1946. It has succeeded in fostering strategic relationships with countries such as Israel, Saudi Arabia and the United States. But this stability is a delicate balance, and the country faces a constant uphill struggle against its geographic constraints as it seeks to provide for its population and manage its security.