This essay compares the national space legislation of China, Japan, and the Republic of Korea (ROK), outlining the reasons behind the legislation and then explaining what it authorizes, the jurisdiction it asserts, and the conditions it imposes on nongovernmental space activities. The essay also compares the compensation available to victims in case of damages and governmental indemnification payments to protect victims and the space launch industry in Japan and the ROK. Differences in industry policies and dates of enactment help to account for variations among these states. However, the comparative analysis suggests that the domestic legal conditions across Asia's three spacefaring nations are similar to those found worldwide.

Both national and international laws apply to collisions by space vehicles and objects in outer space and with the surface of the Earth. International treaties govern collisions involving commercial operators from different states, while domestic laws govern claims by nationals against national commercial operators. Commercial operators may find themselves as defendants or become plaintiffs when others cause them damage. This essay discusses liability in the new space era from the point of view of these operators, including both outer space and surface liabilities. It examines liability exposure, describes different regimes governing liability, and identifies prospective legal changes.

The United States’ enactment of the Space Resource Exploration and Utilization Act of 2015 marked a significant turn in the evolutionary course of space lawmaking, although not for the reasons commonly cited. The Act is noteworthy not for its substance, but as a symptom of emerging structural change in how space law is made, and by whom. Using space resources as a case study, this essay charts this evolutionary shift in space lawmaking and assesses its implications for the international regime on which a growing and increasingly diverse range of space operators depend.

As the number and intensity of space activities increase, so will the need for rules on Space Traffic Management (STM). Emerging technologies such as mega-constellations, which are satellite constellations consisting of hundreds or even thousands of satellites, may stretch the limits of the current informal coordination system. The goal of this essay is to discuss the critical elements of a system of STM that would, through standardization, establish trust in the resulting system. The standardization elements will be divided into three categories: data standards, processing standards, and legal standards. I argue that a system of STM requires standardized practices that are based on a strong technical foundation in order to enhance trust among space actors. After discussing the types of standards that are needed for STM, I turn to possible paths for achieving a globally effective STM system.

Once the domain of a few spacefaring nations, outer space has exploded with new actors, state and private, in recent years. New actors and activities bring new potential threats and concerns for new and existing actors alike. In this complex environment, where mistrust and misunderstanding often prevail, international law can play an important role in bridging gaps and creating predictability, clarity, and consistency. Although new treaty law is unlikely, the ordinary incremental international law processes of state practice, opinio juris, and international jurisprudence will help to resolve critical questions about the content and application of international law in outer space over time.

The United States and other actors such as the European Union impose “targeted sanctions” against foreign officials for acts carried out in their official capacity, or against legal entities of targeted states. This mirrors the practice and experience of the United Nations. The Security Council's practice of imposing comprehensive sanctions in the early 1990s quickly evolved into a practice of “targeted” or “smart” sanctions, to both improve effectiveness and to alleviate the significant effects of sanctions on the population of targeted states. However, the legal regime for resorting to sanctions is different when it comes to states acting unilaterally than it is for collective action within the framework of the UN Charter. This essay first clarifies some terminological issues. It then delves into the legality of the practice of unilateral “targeted sanctions,” and concludes that the most legally difficult aspect of these measures is their purported extraterritoriality.

Enforcement by way of unilateral economic sanctions has been described as “one of the least developed areas of international law.” The term “sanctions” is notoriously difficult to define and does not itself appear in the key international instruments. With economic sanctions regularly referred to as President Trump's “weapon of choice,” and with opposition to such measures growing, greater certainty is needed in this area of law if the legitimacy and effectiveness of sanctions are to be preserved. This essay distinguishes UN-authorized sanctions from three types of “autonomous” sanctions (collective corrective sanctions, unilateral corrective sanctions, and unilateral coercive sanctions) and argues that many uses of unilateral sanctions are either unregulated or based on questionable legality.

Financial and economic sanctions are often adopted to serve multiple ends, including deterrence and prevention, but they are best understood as a tool to incentivize change in a target's behavior. In pursuit of this coercive objective, it is generally—but not always—the case that sanctions are more effective when they are imposed multilaterally, and the broader the coalition the better. This is because multilateral sanctions leverage the diverse sources of pressure that coalition partners can bring to bear on a target and carry with them the legitimacy of broad international support. Taken to its extreme, this argument may suggest that sanctions should always be multilateral, whether adopted through the United Nations, another forum, or an ad hoc coalition. But as we explain below, there are at least two significant reasons that militate in favor of unilateral sanctions. First, within the broad limits of international law, every country must retain the authority to impose sanctions to protect its sovereign security interests, even when it cannot muster a coalition of like-minded allies or a sufficient number of votes—and avoid a veto—on the UN Security Council. Second, imposing “smart” sanctions is actually a difficult business, requiring a complex administrative apparatus to design, build, implement, enforce, and defend them. International institutions, including the United Nations, are inherently less able to build the necessary structures to effectively enforce sanctions. For all of these reasons, two systems of sanctions—one national, one supranational—will likely coexist into the future.

With the Trump administration's reimposition of financial sanctions on Iran, the power of the weaponized dollar is yet again making headlines—and putting distance between the United States and its allies. The dollar's special status as the world's key currency affords the United States an unrivaled sanctioning power. Because access to dollars is a near-necessity for multinational businesses and financial institutions, the United States can unilaterally impose costly sanctions by denying such access to a target—whether a state, company, or individual. This capability is one form of the “exorbitant privilege” afforded to the United States by the dollar's international role. This essay considers why the dollar's status affords the United States this sanctioning power and how the United States exercises it. I first summarize the nature of the dollar's role. Next, I explain the means by which the United States has weaponized that role, especially through financial sanctions. I conclude by offering some potential limitations on that power and exploring the ways in which other countries might seek to erode it.

The United States has employed targeted sanctions—economic and travel restrictions imposed directly on natural and legal persons—in a wide range of policy areas in the past two decades. This includes counterterrorism, nonproliferation, and cyber, as well as sanctions regimes aimed at changing the behavior of various governments. A substantial literature has considered the compatibility with international human rights law of the targeted sanctions practices of other actors, particularly the UN Security Council and the European Union. But relatively few scholars have examined U.S. targeted sanctions practices from that perspective. This essay argues that in principle, current U.S. designation practices can be reconciled with international standards. However, a more robust conclusion about the practices’ compatibility with international human rights law would require more information on the application of designation procedures in individual cases.

In the international legal order, sanctions are valued for their coercive and stigmatizing functions. Through the imposition of financial or other costs, these measures seek to induce compliance with international law by those who are targeted. They also aim to signal the sender's commitment to the violated norm and stigmatize an actor responsible for wrongful behavior. In light of these functions, this essay examines the factors to assess when evaluating the efficacy of unilateral targeted sanctions in enforcing international law. The issue is relevant not only for political scientists, but also for international lawyers interested in ensuring compliance with international norms.

Why does Wüsthof sell a fancy kitchen knife for US$2000, but mass-produce something similar for US$100? Why do some of us mail holiday cards, while sending anything similar by email? Why does the American Journal of International Law print its journal, when interested readers—and there should be many—can read articles like Julian Nyarko's “Giving the Treaty a Purpose: Comparing the Durability of Treaties and Executive Agreements” online? Come to think of it, why bother with Article II treaties, when they too have a near substitute, more easily produced, in congressional-executive agreements? On this last question, Nyarko's article offers an interesting approach and an intriguing finding: if we measure the commitment strength of agreements in terms of duration, treaties are measurably longer and, perhaps, stronger. Having spent several years working on treaty issues for the Restatement (Fourth) of the Foreign Relations Law of the United States, I am acutely (and perhaps embarrassingly) interested in finding out why they matter. In this essay, I note some misgivings about how the article reckons the substitutability of agreements and about treating their age as a proxy for strength—perhaps Methuselah rivaled Samson's might at some point, but that was not how he distinguished himself—before closing by trying to imagine rival inferences that might be consistent with Nyarko's valuable insights.

In “Giving the Treaty a Purpose,” Julian Nyarko distinguishes between treaties and executive agreements and argues that treaties signal a higher level of commitment to our partners in cooperation than do executive agreements because treaties are more durable. Nyarko uses survival-time analysis to demonstrate that treaties last longer than executive agreements—that is, treaties are less likely to drop out of the Treaties in Force (TIF) series in any given year. The longer life of treaties is Nyarko's proxy for their greater durability. Nyarko argues that his result holds “even after controlling for a number of covariates that could influence the durability of the agreement,” like particular presidents, subject areas, and partner countries as well as the degree of divided government. Nonetheless, Nyarko's list omits the most important variable affecting durability as he defines it: intended duration. Sometimes the intended duration of a piece of formal international law is finite. Indeed, as I will explain in this response, under certain (and common) conditions, this choice of a finite duration is what makes the commitment credible (or, in Nyarko's language, reliable).

When I finished reading Julian Nyarko's “Giving the Treaty a Purpose: Comparing the Durability of Treaties and Executive Agreements,” I found my mind wandering through memories of the more than five years I spent working on Capitol Hill as Counsel for the Senate Foreign Relations Committee (SFRC)—a role that often required me to figure out how best to preserve the constitutional prerogatives of Congress in the face of the various types of international agreements the executive branch produced. This essay recounts my impressions of how the Senate handled different agreements in the 2013–2018 timeframe—Article II treaties, the Paris Climate Agreement, and the Iran Nuclear Agreement. Unlike Professor Nyarko's ambitious and impressive work to categorize and statistically analyze the durability of Article II treaties and executive agreements—which I applaud and find useful—this essay is modest in purpose. I contend that how Congress handles different types of agreements is largely a product of specific political dynamics—including political ownership, policy entrepreneurism, and electoral risk—that can be unpredictable. Because of these dynamics, the differences that Nyarko reveals regarding the durability of Article II treaties and executive agreements are unlikely to produce a significant change in official practice.

Attributing computer network intrusions has grown in importance as cyber penetrations across sovereign borders have become commonplace. Although advances in technology and forensics have made machine attribution easier in recent years, identifying states or others responsible for cyber intrusions remains challenging. This essay provides an overview of the attribution problem and its international legal dimensions and argues that states must develop accountable attribution mechanisms for international law to have practical value in this sphere.

When the responsibility of more than one state is engaged in relation to a wrongful cyber operation, the relevant states share responsibility for it. Shared responsibility can arise, for instance, when multiple states jointly conduct a cyber operation or when one state is involved in the cyber operation of another state (e.g., by providing assistance or exercising control). In view of the persistent difficulties associated with attribution of cyber conduct, shared responsibility can be a useful analytical framework to broaden the net of possible responsible states in relation to a cyber operation.

In late 2018, the U.S. Secretary of Homeland Security suggested that “cyber-attacks now exceed the risk of physical attacks.” Yet the law has not kept pace with this reality. In particular, identifying who is responsible for a cyberattack makes it difficult to regulate this conduct. A state often cannot practically respond to a threat unless it knows from where the threat emanates and potentially who is responsible. Attribution of cyber conduct is critical from a legal perspective because the unlawful act must be attributable to another state for state responsibility to be engaged.