Key Takeaways
- The Alien Tort Statute does not permit judicial creation of new private causes of action for international torts in violation of the “law of nations,” reinforcing the potency of separation of powers arguments.
- By “closing the door” on new Alien Tort Statute causes of action for primary liability, Cisco bars claims for related aiding-and-abetting liability.
- The Torture Victim Protection Act of 1991 categorically does not provide a cause of action for aiding-and-abetting liability.
On June 23, Justice Amy Coney Barrett, writing for a six-justice majority, held that federal courts may not create new causes of action under the Alien Tort Statute for international harms; the Supreme Court further held that the plain text of the Torture Victim Protection Act does not permit aiding-and-abetting liability.[1]
A Judicial History of the Alien Tort Statute
The Alien Tort Statute (ATS)[2] was enacted in 1789 and gives federal district courts jurisdiction over “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.” The First Congress sought to provide a federal forum for delicate foreign-relations disputes, such as attacks on foreign officials and other violations of the “law of nations.” ATS cases “by their nature” implicate foreign policy.[3]
For nearly two centuries, the ATS remained largely dormant until the Second Circuit’s 1980 decision in Filártiga v. Peña-Irala.[4] There, the court permitted an ATS suit by foreign plaintiffs against a foreign defendant for violations of international law – specifically, torture. The court rooted its analysis not in an express cause of action or a “grant[] [of] new rights” but instead held that jurisdiction was appropriate because the ATS “open[ed] the federal courts for adjudication of the rights already recognized by international law.”[5] Because deliberate torture under color of official authority violates universally accepted norms of international law, the court held that the ATS provides federal jurisdiction.[6]
The U.S. Supreme Court first interpreted the ATS in modern history in 2004. In Sosa v. Alvarez-Machain, the Court held that the ATS does not permit courts to create new causes of action for arbitrary detention in violation of international law.[7] At the same time, Sosa attempted to reconcile Filártiga by recognizing that the ATS is “a jurisdictional statute creating no new causes of action,” while also allowing courts to retain narrow authority to recognize certain implied causes of action for sufficiently definite and accepted international norms.[8] In light of this tension, Sosa proposed a two-step framework under which a plaintiff must first show that the norm has a “definite content and acceptance among civilized nations,”[9] and then show that it would be prudent for the court to create the proposed cause of action when the political branches have not acted.[10] Though the Court acknowledged that “the modern line of cases beginning with Filártiga” does not “categorically preclude[] federal courts from recognizing a claim under the law of nations as an element of common law,” it emphasized that there is “no basis to suspect Congress had any examples in mind beyond those torts corresponding to [Sir William] Blackstone’s three primary offenses: violation of safe conducts, infringement of the rights of ambassadors, and piracy.”[11]
Since Sosa, the Court has continued to narrow the ATS’ scope, repeatedly rejecting claims asserted under the statute. In Kiobel v. Royal Dutch Petroleum Co., the Court held that ATS claims are subject to the presumption against extraterritoriality; thus, those “seeking relief for violations of the law of nations occurring outside the United States” are barred.[12] The Court reiterated that principle in Nestlé USA, Inc. v. Doe, holding that “allegations of general corporate activity . . . cannot alone establish domestic application of the ATS.”[13] And in Jesner v. Arab Bank, PLC, the Court refused to extend ATS liability to foreign corporations.[14]
Secondary Liability for International Harms
Consistent with this narrowing of primary liability under the law of nations, the Supreme Court has also significantly curtailed secondary liability for international tort claims. Two recent holdings are illustrative: Twitter v. Taamneh,[15] and Smith & Wesson Brands, Inc. v. Estados Unidos Mexicanos,[16] which both evaluated – and declined to impose – aiding-and-abetting liability under, respectively, the Justice Against Sponsors of Terrorism Act (JASTA)[17] and the Protection of Lawful Commerce in Arms Act (PLCAA).[18]
In Twitter, plaintiffs sued three social-media companies for aiding and abetting an ISIS terrorist attack in the Reina nightclub in Istanbul.[19] Plaintiffs alleged that ISIS used defendants’ platforms to solicit funds, recruit terrorists, and spread propaganda; plaintiffs further alleged that defendants knew of this use but continued to host ISIS content, amplify it through algorithms, and profit from advertising.[20] The Court held that aiding-and-abetting liability requires “conscious, voluntary, and culpable participation” in the specific underlying terrorist attack in a way that helps it succeed, and that plaintiffs’ allegations did not state a viable aiding-and-abetting claim because they did not plead – as required by the statute – that the defendant provided “knowing and substantial assistance” to the primary tortfeasor for the specific attack.[21] The Court made clear that JASTA requires an articulable nexus between the defendant’s act and the alleged harm,[22] which can be made by a showing of “direct and extraordinary” assistance. Plaintiffs’ claims failed this high bar: there were no allegations that defendants gave ISIS “special treatment or words of encouragement,” and ISIS used the platforms “just like everyone else.”[23] Nor did plaintiffs plausibly allege that defendants “associated themselves” with the attack, participated in it as something they wished to bring about or sought to make it succeed.[24] Defendants’ relationship with ISIS was “arm’s length, passive, and largely indifferent,” and their connection to the Reina attack was “highly attenuated.”[25] “[T]he more attenuated the nexus, the more courts should demand that plaintiffs show culpable participation through intentional aid that substantially furthered the tort.”[26]
The Court applied similar reasoning in Smith & Wesson Brands, Inc. v. Estados Unidos Mexicanos,[27] holding that plaintiffs failed to plead that gun manufacturers aided and abetted unlawful sales to Mexican cartels, despite allegations of knowledge and continued supply. The Court explained that when liability is based on aiding and abetting “a broad category of misconduct,” the defendant’s participation must be “pervasive, systemic, and culpable,” effectively aiding every wrongful act of the tortfeasor.[28] An “ordinary merchant” does not become liable for criminal misuse of its goods, even with some knowledge of misuse, and is liable only if it takes active steps to promote the resulting crime.[29]
Cisco Systems, Inc. v. Doe I
The Court’s decision in Cisco builds on the foundation established in its recent ATS decisions – Kiobel, Nestlé, and Jesner – and reflects the same underlying rationale applied in Twitter and Smith & Wesson. In Cisco, plaintiffs alleged that they were persecuted by the Chinese government and that defendants enabled that persecution by developing surveillance technology used to identify and apprehend them.[30] Plaintiffs brought claims under the ATS alleging aiding-and-abetting liability, and one plaintiff also asserted claims under the Torture Victim Protection Act of 1991 (TVPA).[31] The district court dismissed the complaint, but the Ninth Circuit reversed in relevant part, concluding that aiding-and-abetting liability is sufficiently definite and universal to be viable under the ATS and that the TVPA encompasses such claims.[32]
The Supreme Court reversed.[33] Addressing the ATS first, the Court emphasized that it has “repeatedly turned away plaintiffs asserting claims under the ATS” and has “never—not once—created an ATS cause of action.”[34] Because the ATS “is a jurisdictional statute” only, it does not permit courts to create new private causes of action for violations of international law and is instead limited to common law offenses recognized when the statute was enacted, i.e., the Blackstone “three” – violation of safe conducts, infringement of the rights of ambassadors, and piracy.[35] The Court noted that “the power to create causes of action belongs to Congress” and that Congress is “better positioned than courts to evaluate the policy tradeoffs of creating liability.”[36] The Court then held that because “[c]ourts cannot create new rights of action to remedy violations of international law, . . . there is necessarily no liability for aiding and abetting such violations.”[37] Sosa required “great caution in adapting the law of nations to private rights,” and the Court has since “rejected the practice of fashioning rights of action as we see fit.”[38]
The Court also found that the text of the TVPA does not mention – and therefore does not permit – aiding-and-abetting liability. Plaintiffs argued that the TVPA provides a cause of action against someone who “subjects” another to torture and that “subjects” is broad enough to include aiding-and-abetting liability. The Court patently rejected this theory: “The TVPA nowhere mentions aiding-and-abetting liability, and that silence is enough to settle the issue.”[39]
Conclusion
Read collectively, Twitter, Smith & Wesson, and Cisco establish a reinforced defense framework – across distinct statutory contexts – for companies accused of facilitating international or cross-border harms. Twitter narrowed JASTA aiding-and-abetting liability by requiring conscious, culpable participation in a specific wrongful act or, in rare cases, pervasive and systemic assistance to an illicit enterprise that reflects sufficiently culpable participation in the underlying tort. Smith & Wesson applied similar principles in the PLCAA context to reject claims based on downstream misuse of lawful products, emphasizing that generalized sales practices, failures to supervise, and ordinary product-design decisions do not suffice.
Cisco goes further: it prohibits judicial creation of new causes of action under the ATS for violations of the law of nations and holds that there can be no aiding-and-abetting liability under a newly hypothesized ATS claim. The decision’s TVPA holding also confirms that aiding-and-abetting liability must come explicitly from Congress and not by implication or judicial interpretation.
The practical implications are significant. Plaintiffs seeking to hold corporate defendants liable for alleged global harms will face increasingly demanding threshold barriers. They must identify an express cause of action authorized by Congress, plead a cognizable theory of secondary liability, and overcome the Court’s concerns about separation of powers, sufficient levels of culpability, and judicial intrusion into foreign affairs. For corporate defendants, these decisions provide multiple grounds for early dismissal, including lack of a cause of action, lack of statutory authorization for secondary liability, failure to plead culpable participation, insufficient nexus to the alleged harm, and reliance on theories that would transform ordinary commercial activity into global liability.
[1] Justice Ketanji Brown Jackson joined the majority opinion with respect to the Torture Victim Protection Act holding only.
[2] 28 U.S.C. § 1350.
[3] Cisco Sys., Inc. v. Doe I, 609 U.S. ___, 2026 WL 1791225, at *6 (June 23, 2026).
[4] 630 F.2d 876.
[5] Id. at 887.
[6] Id. at 890.
[7] 542 U.S. 692, 724.
[8] Id. at 724–25.
[9] Id. at 732.
[10] Id. at 736. The Cisco decision notes that the first step was “an effort to head off judicial creativity with respect to the norms themselves” and the second step was “a warning that courts must tread lightly, because creating rights of action is Congress’s prerogative, and foreign policy is the political branches’ domain.” 2026 WL 1791225, at *5.
[11] Id. at 724.
[12] 569 U.S. 108, 124 (2013).
[13] 593 U.S. 628, 634 (2021).
[14] 584 U.S. 241, 272 (2018).
[15] 598 U.S. 471 (2023).
[16] 605 U.S. 280 (2025).
[17] Pub. L. No. 114-222, 130 Stat. 852 (2016).
[18] 15 U.S.C. § 7902(a).
[19] 598 U.S. at 478–79.
[20] Id. at 480–82.
[21] Id. at 494, 497–98.
[22] Id. at 506.
[23] Id. at 498.
[24] Id. (quoting Nye & Nissen v. United States, 336 U.S. 613, 619 (1949)).
[25] Id. at 500.
[26] Id. at 506.
[27] 605 U.S. 280, 292 (2025).
[28] Id.
[29] Id.
[30] Cisco, 2026 WL 1791225, at *5.
[31] Id. at *9; Pub. L. No. 102-256, 106 Stat. 73 (1992).
[32] 73 F.4th 700, 718, 744 (9th Cir. 2023).
[33] Cisco, 2026 WL 1791225, at *10.
[34] Id. at *5, *8.
[35] Id. at *6, *8.
[36] Id. at *2, *7.
[37] Id. at *9.
[38] Id. at *6-7 (quoting FS Credit Opportunities Corp. v. Saba Capital Master Fund, Ltd., 608 U.S. __, 2026 WL 1686059 (2026)).
[39] Id. at *9 (relying on Central Bank of Denver, N.A. v. First Interstate Bank of Denver, N.A., 511 U.S. 164 (1994)).
