ABSTRACT
The rise of the Islamic State (IS) has dramatically forced a recalculation of security in the Middle East and Persian Gulf by the United States, other Western nations, and regional powers such as Iran or Saudi Arabia. In spite of its initially small size, Western intelligence put its strength at 10-12,000 in 2013, the Islamic State was able to alter the military balance in the Syrian Civil War and launch an offensive that resulted in the capture of significant strategic areas within Iraq. By summer 2015, the organization controlled half of Syria, including all of the major border crossings with Iraq. The military success of the group attracted a growing number of foreign fighters, drawn in some cases by an increasingly sophisticated recruitment strategy that effectively combined a jihadist message with a social media outreach program targeting vulnerable populations in the region and Western nations. Estimates in fall 2014 affirm the growth of the organization with some analysts suggesting 30-40,000 fighters. The Islamic state has prompted renewed US and allied military intervention in Iraq and Syria, and brought the United States into an uneasy relationship with Iran. However, the legacy of the Iraq War has constrained policy options for the United States and other Western powers and resulted in a strategy of over-the-horizon strikes designed to prevent defeat and stabilize the region, as opposed to achieving victory and defeating the IS.
