The United Arab Emirates is located on the southwestern edge of the Arabian Peninsula. To its west is Saudi Arabia and to its east is Oman. Iran is only a few miles north, across the Persian Gulf. With desert in its west and south, dry mountains in its east and the warm waters of the Persian Gulf to the north, the United Arab Emirates' climate is unable to support agriculture beyond small-scale oases and camel herds. The country is divided into three broad regions: the coastal harbors of the Gulf, bounded by the sandy desert of the Rub al-Khali, or Empty Quarter; the interior, where settlements cluster around oases; and the northeast, which is broken up by the Al Hajar Mountains. There are no natural rivers and few timber supplies in the United Arab Emirates, and nearly all the country's drinkable water is trapped beneath oases. In the premodern era, citizens mainly survived off piracy, trade and pearling, and the most powerful settlement was the emirate of Ras al-Khaimah near the Al Hajar Mountains. After the discovery of oil in the 1962, power shifted permanently to the more southern Abu Dhabi, which holds 94 percent of the country's proven oil reserves. These coastal cities are the core of the country. Founder Sheikh Zayed bin Sultan Al Nahyan established the United Arab Emirates — the Arab world's only successful federation — in 1971 and ruled until his death in 2004. At that time, his son and current president Sheikh Khalifa bin Zayed Al Nahyan took over power. The United Arab Emirates seeks to maximize its independence while warding off the influence and control of more powerful regional players Saudi Arabia and Iran. To do this, it has leveraged its energy supply and strategic location to secure alliances with extra-regional powers like the United States. Utilizing its oil receipts, the United Arab Emirates has imported foreign labor from South and East Asia, as well as the Arab world. Combining that labor with global technology, the country has rapidly transformed itself from a desert backwater to a key transport hub, tourist destination and regional military power.