The recent increase in the number of unaccompanied alien children (UACs) apprehended at the border between Mexico and the United States has raised questions about the role that gang-related violence in Central America may play in determining eligibility for refugee status and asylum. Gang activity is wide-spread in El Salvador, Guatemala, and Honduras, and attempts by these governments to control such activity have been seen as ineffective, at best, or as violating the civil rights of persons perceived as gang members or associates, at worst. The Office of the United Nations High Commissioner for Refugees (UNHCR) repeatedly noted this gang-related violence in its 2014 report, Children on the Run: Unaccompanied Children Leaving Central America and Mexico and the Need for International Protection . Subsequently, in discussing the "surge" in the number of UACs arriving at the U.S.-Mexican border in FY2014, the UNHRC reiterated that 58% of these children cite "violence" in their home countries as "at least one key reason" for leaving. Refugee status and asylum are two forms of discretionary relief that could enable UACs to enter or remain in the United States, and the Immigration and Nationality Act (INA) relies upon the same definition in determining eligibility for both. In both cases, to be eligible, aliens must prove that they have experienced past persecution, or have a well-founded fear of future persecution, on account of race, religion, nationality, political opinion, or membership in a particular social group. However, refugee status may only be granted to aliens outside the United States, while asylum may only be granted to aliens arriving at a port of entry or the U.S. border, or within the United States. Applicants for refugee status are also barred from appealing denials of their applications, while applicants for asylum are not. Thus, an equivalent to the extensive body of case law construing and applying the INA's definition of refugee in the context of asylum is lacking in the context of refugee status. Instead, the meaning of refugee for purposes of refugee status is typically construed in light of asylum cases, and asylum is the focus of this report. The report provides an overview of the basis for asylum in U.S. law. It also discusses how key elements of the INA's definition of refugee have been construed and applied in gang-related asylum cases. The report briefly notes, in relevant places, related forms of relief from removal, such as withholding of removal under Section 241 of the INA or the Convention against Torture and Other Cruel, Inhuman, or Degrading Treatment or Punishment, but does not provide a comprehensive treatment of these topics. It is also important to note that many potentially relevant decisions—namely, those by asylum officers within U.S. Citizenship and Immigration Services (USCIS) and immigration judges within the Executive Office for Immigration Review (EOIR) at the Department of Justice (DOJ)—are not published. There are reasons to believe that USCIS and EOIR may be more receptive to gang-related asylum claims than the decisions by the Board of Immigration Appeals (BIA) and the federal courts of appeals discussed here. However, USCIS and immigration judge decisions are not publicly available in the same way that published BIA decisions and federal court decisions are. The INA's current protections for refugees and asylees are grounded in the 1951 Convention Relating to the Status of Refugees and the 1967 Protocol Relating to the Status of Refugees. The Convention generally defined a refugee as any person who [a]s a result of events occurring before 1 January 1951 and owing to well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group, or political opinion, is outside the country of his nationality and is unable or, owing to such fear, is unwilling to avail himself of the protection of that country, although persons who had "committed a crime against peace, a war crime, or a crime against humanity" were expressly excluded from this definition. Most notably, the Convention barred nations which are parties to it from returning refugees to their home country (or another country) where they feared persecution. It also obligated these nations to grant refugees freedom of religion and movement, the right to work and public education, and access to identity papers and travel documents, among other things. Conversely, it required refugees to respect the laws and regulations of their country of asylum. The United States was involved in drafting the Convention, but did not sign on as a party to it. However, it did sign on as a party to the Protocol, which amended the Convention by removing the temporal restrictions (i.e., "events occurring before 1 January 1951") from its definition of refugee . The Refugee Act of 1980 ( P.L. 96-212 ) is widely recognized as having been enacted to bring U.S. domestic law into conformity with the United States' commitments under the Protocol. Among other things, the Refugee Act amended Section 101(a)(42) of the INA to define refugee in largely the same terms used by the Convention and Protocol: The term "refugee" means ... any person who is outside any country of such person's nationality or, in the case of a person having no nationality, is outside any country in which such person last habitually resided, and who is unable or unwilling to return to, and is unable or unwilling to avail himself or herself of the protection of, that country because of persecution or a well-founded fear of persecution on account of race, religion, nationality, membership in a particular social group, or political opinion. The Refugee Act also added the current Sections 207, 208, and 209 to the INA, which, respectively, address refugee admissions, the granting of asylum, and the adjustment of refugees' and asylees' status to that of lawfully permanent resident aliens (LPRs). In addition, the Refugee Act amended then-Section 243 of the INA to generally bar the return of aliens to countries where the "alien's life or freedom would be threatened ... on account of race, religion, nationality, membership in a particular social group, or political opinion." Subsequently relocated to Section 241 of the INA, this prohibition forms the basis for what is referred to as withholding of removal . Withholding of removal under Section 241 of the INA represents the U.S.'s primary obligation under the Convention and Protocol. That is, as a party to the Protocol, the United States is barred from removing aliens, including aliens arriving at the U.S. border, to a county where he or she would be persecuted. The United States is not required, by the Protocol or otherwise, to admit refugees to the United States, grant asylum to persons in the United States, or permit refugees or asylees to adjust to LPR status or obtain citizenship. To the contrary, the INA expressly notes that the granting of asylum is discretionary, and courts have upheld its denial even when an alien fulfills the requirements of the statutory definition of refugee . It is also important to note that, even though the United States signed on as a party to the Protocol, and the INA's definition of refugee generally corresponds to that in the Convention and Protocol, it is U.S. domestic law—not international law—that governs U.S. obligations as to individual aliens. Relatedly, the same terms (e.g., persecution , particular social group ) may be construed differently when used in the Convention and Protocol than when used in the INA. Aliens seeking asylum in the United States have the burden of establishing, by a preponderance of the evidence, that they are "refugees" under the INA's definition of this term. This means showing that they (1) have suffered persecution, or (2) have a well-founded fear of persecution (3) on account of (4) a protected ground (i.e., race, religion, nationality, political opinion, or membership in a particular social group). However, the meaning of certain of these terms—such as persecution and particular social group —is not established by Convention or Protocol, or by the INA and its implementing regulations. Instead, their meaning has been determined by the Board of Immigration Appeals (BIA)—the highest administrative tribunal for interpreting and applying immigration law—through case-by-case adjudication, with the federal courts generally deferring to the BIA's interpretation so long as it is based on a "permissible construction" of the INA. In other cases, such as with the meaning of well-founded fear , the executive branch has interpreted particular language within the INA's definition of refugee through the promulgation of regulations. These regulatory interpretations are also afforded deference by the courts insofar as they are based on "permissible" constructions of the statutory language. In yet other cases, Congress has enacted legislation that affects how particular terms within the refugee definition are construed. Perhaps the most notable example of this is the REAL ID Act of 2005 ( P.L. 109-13 ), which amended the INA to require that a protected ground (e.g., race, religion, nationality) "was or will be at least one central reason" for the persecution. The application of the INA's definition of refugee to aliens seeking asylum in the United States due, in whole or in part, to gang-related violence is, thus, complicated because it involves consideration of an extensive body of statutes, regulations, and administrative and judicial decisions. In addition, the federal courts of appeals can sometimes have differing opinions on whether particular interpretations advanced by the BIA are "permissible" and, thus, entitled to deference.