Congress recently enacted significant reforms to the laws governing the reporting and publication of international agreements in the United States. These reforms were adopted in December 2022 and took effect in September 2023, and the State Department issued regulations implementing them in early October 2023.

The text of the US Constitution appears to require that individual states, to the extent that they are ever allowed to conclude agreements with foreign governments, must obtain congressional approval. In practice, however, states conclude many agreements with foreign governments, including with Canada and its provinces, and they almost never seek congressional approval. This practice is an illustration of both the importance of federalism in US foreign relations and the significant role played by historical practice in informing US constitutional interpretation. The phenomenon of state international agreements assumed new prominence in 2019 when the Trump administration sued to challenge a climate change agreement that the state of California had made with Québec. Despite this challenge, for the most part, neither Congress nor the executive branch has resisted the growth in state international agreements. This acquiescence could change as countries like China target US states in an effort to work around strained relations with the US national government and as states become more assertive in resisting the national government’s foreign policies. In any event, the practice of state international agreements unapproved by Congress rests in part on a distinction between binding and non-binding agreements that deserves greater scrutiny under both domestic and international law.

In April 2019, the U.S. Fish and Wildlife Service (USFWS) released its recovery plan for the jaguar Panthera onca after several decades of discussion, litigation and controversy about the status of the species in the USA. The USFWS estimated that potential habitat, south of the Interstate-10 highway in Arizona and New Mexico, had a carrying capacity of c. six jaguars, and so focused its recovery programme on areas south of the USA–Mexico border. Here we present a systematic review of the modelling and assessment efforts over the last 25 years, with a focus on areas north of Interstate-10 in Arizona and New Mexico, outside the recovery unit considered by the USFWS. Despite differences in data inputs, methods, and analytical extent, the nine previous studies found support for potential suitable jaguar habitat in the central mountain ranges of Arizona and New Mexico. Applying slightly modified versions of the USFWS model and recalculating an Arizona-focused model over both states provided additional confirmation. Extending the area of consideration also substantially raised the carrying capacity of habitats in Arizona and New Mexico, from six to 90 or 151 adult jaguars, using the modified USFWS models. This review demonstrates the crucial ways in which choosing the extent of analysis influences the conclusions of a conservation plan. More importantly, it opens a new opportunity for jaguar conservation in North America that could help address threats from habitat losses, climate change and border infrastructure.

For more than a decade, U.S. courts have struggled to develop a common law immunity regime to govern suits brought against foreign government officials, and they are now divided on a number of issues, including the extent to which they should defer to the executive branch and whether to recognize a jus cogens exception. This Editorial Comment considers a more conceptual division in the courts, between an “effect-of-judgment” approach that would confer immunity only when the judgment that the plaintiff is seeking would be directly enforceable against the foreign state, and a broader “nature-of-act” approach that would confer immunity whenever the plaintiff's case is challenging conduct carried out on behalf of the state. The Comment argues in favor of the nature-of-act approach and explains why analogies in this context to domestic civil rights litigation are misplaced.

This introduction provides an overview of thirteen essays selected in response to a worldwide call for papers for an Agora on “The International Legal Order and the Global Pandemic.” The essays in the Agora consider some of the most pressing challenges, as well as potential opportunities, that COVID-19 is creating for the international legal order. The specific topics addressed include the role of international organizations such as the World Health Organization, state responsibility, human rights, financial regulation, and international trade. Contributors were invited to address the theme from a historical, institutional, doctrinal, normative, critical, or geopolitical perspective, or a mix of perspectives.

Courts in the United Kingdom and South Africa have recently issued important rulings that have constrained the executive's authority to withdraw from treaties in those countries. This essay considers whether these rulings might offer insights for treaty exit issues in the United States. We first provide an overview of U.S. law and practice regarding the termination of international agreements. We next summarize the U.K. and South African decisions, which required parliamentary approval for pulling out of treaties establishing the European Union and the International Criminal Court (ICC), respectively. Finally, we consider the relevance of these rulings for treaty withdrawals in the United States. We conclude that they are unlikely to offer much guidance, both because of differences in the three countries' constitutions and because the reasoning of the U.K. and South African courts do not engage with the central arguments made in the United States concerning the President's unilateral authority to withdraw from treaties.

This essay offers a working definition of “foreign relations law,” describes its various sources, and distinguishes it from international law. It also provides some comparative illustrations of this law and notes some reasons for both commonalities and differences in this law across national jurisdictions. Finally, it discusses the growing emergence of foreign relations law as a field of study outside the United States.

The U.S. executive branch has long declined to recognize any country’s sovereignty over Jerusalem, insisting that the matter be worked out through negotiations between Israel and the Palestinians. The U.S. Congress, by contrast, has tended to support Israeli sovereignty over the city. In 2002, Congress enacted the Foreign Relations Authorization Act for Fiscal Year 2003, Section 214(d) of which provides that, “[f]or purposes of the registration of birth, certification of nationality, or issuance of a passport of a United States citizen born in the city of Jerusalem, the Secretary [of State] shall, upon the request of the citizen or the citizen’s legal guardian, record the place of birth as Israel.” Both the Bush Administration and the Obama Administration declined to comply with this statutory directive. In Zivotofsky v. Kerry (Zivotofsky II), the Supreme Court sided with the executive branch, holding that Section 214(d) unconstitutionally interferes with the exclusive authority of the President to recognize foreign sovereigns.

Nonnative, invasive plants are becoming increasingly widespread and abundant throughout the southwestern United States, leading to altered fire regimes and negative effects on native plant communities. Models of potential invasion are pertinent tools for informing regional management. However, most modeling studies have relied on occurrence data, which predict the potential for nonnative establishment only and can overestimate potential risk. We compiled locations of presence and high abundance for two problematic, invasive plants across the southwestern United States: red brome (Bromus rubens L.) and African mustard (Brassica tournefortii Gouan). Using an ensemble of five climate projections and two types of distribution model (MaxEnt and Bioclim), we modeled current and future climatic suitability for establishment of both species. We also used point locations of abundant infestations to model current and future climatic suitability for abundance (i.e., impact niche) of both species. Because interpretations of future ensemble models depend on the threshold used to delineate climatically suitable from unsuitable areas, we applied a low threshold (1 model of 10) and a high threshold (6 or more models of 10). Using the more-conservative high threshold, suitability for Bromus rubens presence expands by 12%, but high abundance contracts by 42%, whereas suitability for Brassica tournefortii presence and high abundance contract by 34% and 56%, respectively. Based on the low threshold (worst-case scenario), suitability for Bromus rubens presence and high abundance are projected to expand by 65% and 64%, respectively, whereas suitability for Brassica tournefortii presence and high abundance expand by 29% and 28%, respectively. The difference between results obtained from the high and low thresholds is indicative of the variability in climate models for this region but can serve as indicators of best- and worst-case scenarios.

In its decision yesterday in Bond v. United States, the Supreme Court carefully avoided addressing either the constitutional scope of the treaty power or the scope of Congress’s constitutional authority to implement treaties under the Necessary and Proper Clause. The decision is nevertheless important in holding that a federalism-based clear statement requirement, which was originally developed in the context of purely domestic legislation, applies even to legislation implementing a treaty. It also signals more generally (as had earlier decisions such as Medellín v. Texas) that the Court will be attentive to federalism values even in cases involving foreign affairs. In this post, I will highlight both a process point in support of the Court’s clear statement approach and a potential drawback of that approach. I conclude with some miscellaneous observations about the decision.

The five essays in this Agora, written by Jack Goldsmith and myself, Ashley Deeks, Ryan Goodman, Rebecca Ingber, and Michael Ramsey, consider the legal legacy of the Obama administration concerning the use of military force, with respect to both domestic law and international law. Prominent developments during the Obama administration relating to war powers include the administration's defense in habeas litigation of its authority to detain members of Al Qaeda and associated groups in military custody; its increased use of targeted killing outside of active combat areas, in part through frequent missile attacks carried out by drones; its use of military force in 2011 against the regime of Libyan leader Muammar Qaddafi, pursuant to a United Nations Security Council resolution; its deliberations in 2013 about the use of military force against Syria in response to the use of chemical weapons by the regime of Syrian President Bashar al-Assad; and its initiation of a long-term conflict against the Islamic State in 2014. This Agora touches on these and other developments and offers a range of perspectives.

In the fifteen years since the Authorization for Use of Military Force (AUMF) was enacted on September 18, 2001, the Taliban has been removed from power but not eliminated; Osama Bin Laden has been killed and the senior leaders of Al Qaeda as of 9/11 have been captured, killed, or driven underground, although Al Qaeda remains a threat; numerous Al Qaeda affiliates have sprung up around the globe, most notably in Iraq, Yemen, Syria, and Somalia; and most ominously, the Islamic State has arisen from the ashes of Al Qaeda in Iraq to become what the Director of National Intelligence has described as “the preeminent terrorist threat” against the United States “because of its self-described caliphate in Syria and Iraq, its branches and emerging branches in other countries, and its increasing ability to direct and inspire attacks against a wide range of targets around the world.”

Despite massive changes in the geographical scope of the conflict that began on 9/11, the strategy and tactics employed, and the identity of the enemy, the AUMF remains the principal legal foundation under U.S. domestic law for the president to use force against and detain members of terrorist organizations. The AUMF is already the longest operative congressional authorization of military force in U.S. history, and, as of fall 2016, there was no immediate prospect that Congress would move to repeal or update it. With the continued vibrancy of Al Qaeda, its associates, and the Taliban, and with the 2014 presidential extension of the AUMF to cover military operations against the Islamic State, the AUMF is likely to be the primary legal basis for American uses of force for the foreseeable future.

Objectives: Long-term follow-up of the Caries Management System (CMS) protocol demonstrated that regular monitoring and noninvasive management of dental caries is effective in reducing the number of caries-related events over a 7-year period. This analysis complements the authors’ original economic evaluation of the CMS by re-evaluating the per-protocol cost-effectiveness of the CMS approach.

Methods: An individual patient-simulation Markov model was developed previously, based on 3-year randomized-controlled trial (RCT) data, to simulate the incidence and progression of dental caries, and resultant interventions, and to evaluate the lifetime cost-effectiveness of the CMS versus standard dental care from the Australian private dental practitioner perspective (in which the baseline age distribution was similar to that of the Australian population). The 4-year posttrial follow-up data are used to re-evaluate the long-term cost-effectiveness of the CMS in a more real-life setting.

Results: The reduction in caries risk was maintained among those practices within which the CMS protocols were adhered to. The per-protocol model appears to be reasonably accurate at predicting the risk of restorative events in the posttrial follow-up period. The per-protocol lifetime cost per restorative event avoided is AUD1,980 (USD1,409; 1 AUD = 0.71 USD).

Conclusions: The current analysis confirms that the CMS approach is both effective, when the protocols are adhered to appropriately, and cost-effective compared with standard care in the Australian private practice setting.