The United States has mainly had two consistent policies in the Middle-East from the 1980s to the present:
Supporting Israel: Israel is America's main ally in the region, and both Democrats and Republicans support Israel. The U.S. provides military contributions to that country, which is often in conflict with its neighbors. These contributions are crucial for Israel continuos military victories.
Supporting Saudi Arabia instead of Iran: since the founding of the Islamic Iranian Republic, The United States has been a enemy of Iran and viceversa, and Iran is at the same time a geopolitical enemy of Israel and Saudi Arabia. Saudi Arabia and Iran are in fact, often at war in other countries (proxy wars), and the U.S. always supports the former.
