This dissertation aims to investigate the sources of United States (US) foreign policy toward Azerbaijan by examining the relative impact of domestic, geostrategic and structural factors in explaining US foreign policy toward the country. Azerbaijan is one of the newly independent states that emerged after the collapse of the Soviet Union. Despite its small size, the country’s strategic location, vast oil and natural gas reserves, and its conflict with Armenia over the Nagorno- Karabakh region elevated its importance and made Azerbaijan the center of interest for great powers. As the sole superpower after the end of the Cold War, the US has largely followed a unilateral foreign policy agenda. US foreign policy toward the South Caucasus in general, and Azerbaijan in particular, has been marked by inconsistencies, and by a lack of coordination and an unwillingness to take the initiative in crucial issue areas. Most importantly, experts have observed several important shifts in US policy toward Azerbaijan. These shifts can be conceptualized as critical junctures as they represent fundamental changes in the orientation of US policy. The dissertation is focused on these critical junctures as they relate to four main issue areas: the political economy of oil, the security partnership, economic reforms, and human rights. Why did the US disengage from Caspian energy issues after the successful completion of the Baku-Tbilisi-Ceyhan pipeline? Why did the US lose its commitment to Azerbaijani security, including the peaceful resolution of the Nagorno-Karabakh conflict? Why did the US grow unhappy about the investment climate in Azerbaijan in the 2000s? Why did the Obama administration decide to shift to a “human rights policy” toward Baku, despite two decades of neglect of such issues by the Clinton and Bush Administrations? This dissertation follows a chronological format and analyzes the sources of US foreign policy towards Azerbaijan in three time periods: 1991-2001, 2002-2007, and 2008-2015.