O riginally enacted by the First Congress as part of the Judiciary Act of 1789, the Alien Tort Statute (ATS) has been described as a provision that is "u nlike any other in American law" and "unknown to any other legal system in the world." In its current form, the complete text of the ATS provides that "[t]he district courts shall have original jurisdiction of any civil action by an alien for a tort only, committed in violation of the law of nations or a treaty of the United States." Although it is only a single sentence long, the ATS has been the subject of intense interest in recent decades, as it evolved from a rarely used jurisdictional statute to a prominent vehicle for foreign nationals to seek redress in U.S. courts for human rights offenses and acts of terrorism . T his report examines the development of the ATS, beginning with its origins in the First Congress and continuing through to the Supreme Court's recent decision in Jesner v. Arab Bank, PLC , where the Court held that foreign corporations are not subject to ATS liability. Deconstructed, the ATS statute provides federal district courts with jurisdiction to hear cases with four elements: (1) a civil action (2) by an alien (3) for a tort (4) committed in violation of the law of nations or a treaty of the United States. The significance of these requirements is as follows: 1. A c ivil action : The ATS allows only for civil (rather than criminal) liability. 2. By an alien : A crucial, distinctive feature of the ATS is that it provides jurisdiction for U.S. courts to hear claims filed only by aliens (i.e., non-U.S. nationals). The ATS does not provide jurisdiction for suits alleging torts in violation of the law of nations by U.S. nationals —although other statutes may allow for such claims. 3. For a tort : As a general matter, a tort is "a civil wrong, other than breach of contract, for which a remedy may be obtained, [usually] in the form of damages[.]" 4. In violation of the law of nations or a treaty of the United States : The ATS requires that the tort asserted be considered a violation of either the "law of nations" or a treaty ratified by the United States. The term "law of nations" is now often understood to refer to "customary international law." As a general matter, customary international law is international law that is derived from "a general and consistent practice of States followed by them from a sense of legal obligation." State practices that form the basis for customary international law are often referred to as international "norms." But the process of identifying what norms are actionable under the ATS is a complex judicial function that was the subject of much debate and was addressed by the Supreme Court in Sosa v . Alvarez - Machain , discussed below. Under Article III of the Constitution, Congress is empowered (but not obligated) to create a system of federal courts inferior to the Supreme Court. As one of its first official duties, the First Congress passed legislation, now known as the Judiciary Act of 1789 (Judiciary Act), creating a system of federal district and circuit courts. The original iteration of the ATS was included in Section 9 of the Judiciary Act—a provision which broadly addressed the jurisdiction of the federal district courts. Congress made minor modifications to the ATS in 1873 and 1911. The current version, quoted above, was enacted in 1948 . According to the Supreme Court, the ATS "was intended to promote harmony in international relations by ensuring foreign plaintiffs a remedy for international-law violations in circumstances where the absence of a remedy might provoke foreign nations to hold the United States accountable." During the early years of the Republic, between the end of the Revolutionary War and the adoption of the Constitution, the United States faced a number of difficulties meeting its obligations regarding foreign affairs. Under the Articles of Confederation, the federal government had little ability to provide redress to foreign citizens for violations of international law. Instead, the Confederation Congress passed a resolution recommending that each state create judicial tribunals to hear civil and criminal claims arising out of violations of the law of nations, and that state legislatures criminalize treaty infractions and other breaches of international law. But only one state, Connecticut, passed legislation creating penalties for violations of the law of nations. At the same time, international law during the founding era was understood to place an affirmative obligation on the United States to redress certain violations of the law of nations, even when those violations were perpetrated by private individuals. The Framers expressed concern that the state governments did not fully understand or appreciate the duties that arose under international law by virtue of the United States' new position as a sovereign nation. These concerns led the Framers and the First Congress to provide jurisdiction to federal courts in a number of circumstances that may implicate foreign relations concerns—such as suits involving foreign diplomats, admiralty and maritime cases, and disputes between U.S. citizens and citizens of foreign nations. The ATS was included among those class of jurisdictional provisions designed to provide a forum for federal courts to hear claims for violations of international law when the absence of such a forum could impact U.S. foreign relations. In the 1780s, two incidents involving foreign diplomats highlighted the potential for conflict in international relations under the Articles of Confederation. In 1784, a French "adventurer," Julien de Longchamps, assaulted a French diplomat, François Barbé-Marbois ( Marbois ), on a public street in Philadelphia. Because no national judiciary existed at the time, any case against Longchamps could occur only in a Pennsylvania state court. Concerned that Pennsylvania officials may not adequately address the incident—especially after Longchamps briefly escaped following his arrest —the chief French diplomat in the United States lodged a protest with the Confederation Congress and threatened to leave the country unless an adequate remedy were provided. Longchamps was eventually recaptured, convicted, and sentenced to two years in jail by a Pennsylvania court. But Pennsylvania officials declined French requests to deliver Longchamps to French authorities, and the Confederation Congress passed a resolution directing the Secretary of Foreign Affairs to apologize to Marbois for its limited ability to provide redress at the federal level. Three years later, similar tensions arose when a New York constable entered the home of the Dutch Ambassador and arrested one of his domestic servants. When the Ambassador, Pieter J. Van Berckel, protested that his servant should have been afforded diplomatic immunity, U.S. Secretary of Foreign Affairs John Jay reported to Congress that the federal government was not "vested with any Judicial Powers competent" to adjudicate the propriety of the constable's actions. The United States was "embarrassed" by these incidents and by "its inability to provide judicial relief to the foreign officials injured in the United States[.]" Moreover, such incidents were not seen as low-level diplomatic quarrels. During the founding era, assaults on ambassadors (among other violations of international law) were considered "just causes of war" if not adequately redressed. Some dispute whether the Marbois and Van Berckel incidents were an impetus for the ATS . But the Supreme Court interpreted the ATS as part of a class of provisions in the Judiciary Act that was designed, at least in part, to respond to concerns that the federal government under the Articles of Confederation was unable to provide a judicial forum to protect the rights of foreign diplomats. Regardless of its original purpose, the ATS was rarely used as a source of federal jurisdiction for the first 190 years of its existence. Between 1789 and 1980, litigants successfully invoked the ATS as a basis for jurisdiction in only two reported decisions. The first case, Bolchos v. Darrel , involved a French captain attempting to recover a cargo of slaves he had captured along with a Spanish prize vessel. The second, Adra v. Clift , was brought over 150 years later, and involved the use of forged passports in an international child custody dispute. The dearth of judicial opinions led one federal judge and prominent commentator on federal jurisdiction to describe the statute as "an old but little used section [that] is a kind of a legal Lohengrin . . . no one seems to know from whence it came" —a reference to a Germanic tale involving a knight who appears in a boat drawn by swans to help a noblewoman in distress, but refuses to disclose his origins. After nearly two centuries of dormancy, the ATS sprang into judicial and academic prominence in 1980 after the U.S. Court of Appeals for the Second Circuit (Second Circuit) issued a landmark decision in Filártiga v. Peña-Irala . In that case, two Paraguayan citizens (the Filártigas) brought suit against the former Inspector General of Asuncion, Paraguay, alleging that he had kidnapped, tortured, and killed the plaintiffs' relative in retaliation for their family's support of a political opposition party. The defendant, Americo Norberto Peña-Irala, was also a Paraguayan citizen who was discovered to be living in New York on an expired visa. Relying on the ATS for jurisdiction, the Filártigas contended that Peña-Irala's actions constituted a tort in violation of the law of nations, but the district court initially dismissed the case on the ground that the law of nations actionable under the ATS did not include modern provisions in international law that govern how a nation (in this case, Paraguay) treats its own citizens. In a first-of-its-kind decision, the Second Circuit reversed and concluded that torture by a state official against its own citizen violates "established norms of the international law of human rights" and therefore provides an actionable claim under the ATS.