The Architecture of Accountability: Domestic and International Legal Frameworks Governing U.S. Arms Transfers
The United States occupies a dichotomous role in the global order as both a primary security guarantor and the world’s largest arms exporter. This position creates a profound legal tension when American-manufactured munitions are linked to documented civilian harm in foreign conflicts. As reports of “gross violations of human rights,” or GVHR, surface in modern theaters of war, the legal community must grapple with the threshold for legal responsibility, both concerning the state and its individual actors, when providing the means for violations of International Humanitarian Law (IHL). The following analysis examines the intersection of domestic statutes, such as the Arms Export Control Act (AECA) and the Leahy Laws, with international standards of state responsibility and individual criminal liability. While the political question doctrine often shields these transfers from domestic judicial review, the evolving interpretation of customary international law suggests a narrowing window for legal impunity.
The primary mechanism for regulating the flow of American weaponry is the Arms Export Control Act (AECA), which authorizes weapons transfers only for reasons of legitimate self-defense or internal security. [1] However, the definition of “legitimate” is malleable, often influenced by geopolitical crises, which leads to a reliance on the Conventional Arms Transfer (CAT) policy. The 2023 CAT policy revision signifies a shift in executive branch priorities, requiring a weighing of the risk of civilian harm against strategic interests. The most specific domestic constraints are found in the Leahy Laws, which prohibit the U.S. from providing assistance to foreign security force units if credible intelligence indicates that the unit has committed a GVHR. This involves a rigorous vetting process, though the law allows for the resumption of aid if the foreign government takes effective steps to bring responsible members to justice. Legal experts, including those at the American Bar Association, note that these laws require a rigorous interpretation of how the AECA and Leahy Laws should function when evidence of civilian harm arises.
Beyond domestic statutes, the U.S. is influenced by the principles of state responsibility under international law. Article 16 of the Draft Articles on State Responsibility (ASR) asserts that a state which “aids or assists” another in the commission of an internationally wrongful act is responsible if it does so with knowledge of the circumstances. A central debate in this application is whether the assisting state must possess intent or merely constructive knowledge of how weapons are being used. Legal theorists, such as Oona Hathaway, argue that the “knowledge” threshold is critical in determining when one state is complicit in another's war crimes. [2] Furthermore, while the U.S. is not a state party to the Arms Trade Treaty (ATT), the treaty influences global customary norms regarding the prevention of war crimes. This aligns with the International Committee of the Red Cross (ICRC) Customary IHL Rule 144, which discusses the obligation of states to ensure respect for IHL, often interpreted as a prohibition on providing the weapons employed to violate it. [3]
The question of accountability extends to individual criminal responsibility and the potential liability of U.S. officials. International Criminal Court (ICC) jurisprudence has long debated the “substantial effect” test versus the “specific direction” requirement in aiding and abetting war crimes. High-level decision-makers may face scrutiny for authorizing transfers when evidence of civilian harm is well-documented. Despite these frameworks, legal challenges in U.S. courts often fail due to the justiciability gap. Under the political question doctrine, courts frequently dismiss arms transfer challenges, viewing them as matters of foreign policy reserved for governmental entities. Historical precedents, ranging from Nicaragua v. United States 1986 I.C.J. 14 (1986) to contemporary conflicts in Yemen and Gaza, illustrate how this doctrine limits judicial oversight. Nevertheless, as the substantial effect of American weaponry becomes more visible, the gap between strategic interest and legal liability may begin to close under the weight of evolving customary norms.
Edited by Sophia Berg
Endnotes
[1] American Bar Association. Human Rights, Civilian Harm, and Arms Sales: A Primer on U.S. Law and Policy. Washington, DC: Center for Civilians in Conflict, February 2022. https://civiliansinconflict.org/wp-content/uploads/2022/02/US-Law-and-Arms-Transfers_Final.pdf
[2] Hathaway, Oona A., et al., "Ensuring Responsibility: Common Article 1 and State Responsibility for Non-State Actors," Texas Law Review 95 no. 539 (2017).
[3] International Committee of the Red Cross (ICRC). “Rule 144: Ensuring Respect for International Humanitarian Law.” Customary IHL Database. https://ihl-databases.icrc.org/en/customary-ihl/v1/rule144