The Islamic State (IS, aka the Islamic State of Iraq and the Levant, ISIL/ISIS, or the Arabic acronym Da'esh) is a transnational Sunni Islamist insurgent and terrorist group that controls large areas of Iraq and Syria, has affiliates in several other countries, has attracted a network of global supporters, and disrupts international security with its campaigns of violence and terrorism. The U.S.-led coalition military campaign against the Islamic State organization in Iraq and Syria has adapted since 2014, as Administration officials and coalition partners have implemented changes in strategy and tactics that have reduced the area controlled by the group and eliminated thousands of its personnel. While the Islamic State has suffered losses on the ground in Iraq, Syria, and Libya, a series of terrorist attacks attributed to the group or to individuals it has inspired have claimed hundreds of lives on four continents since November 2015, including in the United States. A number of countries, including the United States, share an interest in further weakening the group and preventing future attacks. Members of Congress, executive branch officials, and their international counterparts continue to debate a range of proposals for extending battlefield gains made to date and preventing the Islamic State from succeeding in its stated objectives of "remaining and expanding." President Obama's goals for U.S. strategy were to "degrade and ultimately defeat" the Islamic State through U.S. direct military action and support for local partner forces. The U.S. military has conducted operations against the group in Iraq, Syria, and Libya. Parallel U.S. diplomatic efforts have promoted political reconciliation in each country among local factions. In other countries, such as Egypt and Nigeria, the United States provides security assistance to partner governments in support of operations against Islamic State affiliates. Evolving counterterrorism cooperation and intelligence sharing efforts among a wider network of concerned governments seek to further limit the ability of IS supporters to carry out transnational terrorist attacks. President-elect Donald Trump has signaled that his Administration may reexamine and redefine U.S. goals and strategies, with a goal of defeating the Islamic State quickly and decisively. The interdependent nature of conflicts and political crises in Iraq, Syria, and other countries where the Islamic State operates complicates efforts to address and durably eliminate the threats posed by the group. Military operations may eliminate IS fighters and liberate IS-held territory, but underlying political disputes and development challenges that have been exploited by the Islamic State and other extremist groups may remain unaddressed or become amplified if post- conflict reconciliation and reconstruction needs go unmet. Governments may continue to share fears about IS-related transnational terrorist threats, but leaders also may continue to face difficult decisions about the potential risks and rewards of military, law enforcement, surveillance, intelligence sharing, financial, border security, refugee admission, and consular countermeasures. This report provides background on the Islamic State organization, discusses its goals, operations, and affiliates, reviews U.S. legislative and policy debates, and describes select FY2017 legislation.