Perhaps no other word in the international humanitarian law lexicon evokes more interest and emotion than proportionality. How States implement the rule of proportionality is perhaps the most hotly debated aspect of international humanitarian law. The indeterminate nature of the rule allows for its meaning to conform to whatever its reader wants it to mean. This is a consequence of the variables related to key provisions of the rule: How do we assess military advantage? What makes an anticipa...| International Law Studies
This article analyzes the legality of U.S. unilateral seabed mining authorized by Executive Order 14285, signed by President Donald Trump on April 24, 2025, permitting mineral extraction on the U.S. continental shelf and international deep seabed. Critics, including China, the European Union, and the International Seabed Authority, contend that this policy violates international law by circumventing Part XI of the United Nations Convention on the Law of the Sea (UNCLOS), which designates seab...| International Law Studies
Much of the debate surrounding the military use of artificial intelligence (AI) tends to focus on lethal autonomous weapons systems. Those are systems that, once activated, can select and engage targets without further human intervention; sometimes pejoratively called “killer robots.” Moreover, debates often focus on their use and risks in land warfare. This land-warfare focus tends to invoke questions about the systems’ ability to distinguish between combatants and civilians on urban b...| International Law Studies
Outer space is becoming increasingly contested and existing approaches to identifying prohibited force in outer space lack a systematic foundation, hindering their application to novel challenges such as temporary interference with critical satellites or threats involving commercial space actors. This article addresses this gap by developing the first comprehensive, multifactorial legal framework for identifying a prohibited use of force in outer space. This framework provides a structured me...| International Law Studies
The Houthis have carried out an unprecedented assault on commercial shipping and foreign warships operating in international waters off the Arabian Peninsula that has changed the face of maritime terrorism. These waters are a strategic corridor that facilitates international trade and the movement of naval forces from Europe and the Americas to the Middle East and Asia via the Suez Canal. As a result of the Houthi attacks, most shipping companies rerouted their vessels around Africa via the C...| U.S. Naval War College Digital Commons
This article examines whether the U.S. nuclear umbrella provided to allies is currently viable and whether it is time for the United States to share nuclear weapons technology with its allies in the Asia-Pacific to counter the growing nuclear threat posed by China, North Korea, and Russia. The article discusses the current capabilities and nuclear doctrine of States possessing nuclear weapons, as well as Iran’s nascent nuclear weapons program. It then discusses the current international law...| International Law Studies
This essay explores China’s approach to global order. China’s remarkable rise has coincided with increasing engagement with the institutions of global governance. These institutions—in particular the United Nations—make up the core of what U.S. leaders have often referred to as the liberal world order or the rules-based order. Many U.S. officials see China as a deep threat intent on challenging, and perhaps even seeking to replace, this rules-based order. This essay, however, makes th...| International Law Studies
In the Nicaragua Case, the International Court of Justice described coercion as the “very essence of prohibited intervention.” The characterization of coercion as an essential element of non-intervention has become unquestioningly accepted by States and scholars and has dominated debates on how the prohibition on intervention applies in various contexts, including in relation to economic sanctions and cyberoperations. This article challenges the ICJ’s assertion. It does so by retracing ...| International Law Studies
The Newport Manual on the Law of Naval Warfare, Second Edition, is a continuing effort to restate the law of naval warfare as a purely lex lata exercise. Like the first edition of 2023, it is designed to provide a practical guide for commanders and seafarers, lawyers and officials, and educators and students. In doing so, the Manual includes developments in warfighting technologies in recent decades, which have significantly influenced the nature of war at sea. This second edition has been ed...| U.S. Naval War College Digital Commons
Combating sabotage of submarine cables and pipelines is a matter of law enforcement, subject to the international law of the sea. However, such acts may also constitute the use of force and an armed attack under Articles 2(4) and 51 of the UN Charter. The application of these concepts requires clarification of the “international relations” in which the use of force takes place and identification of the State against which the armed attack occurs. This article argues that, in the absence o...| International Law Studies
Since 2022, there have been several incidents of apparent intentional damage to submarine cables and pipelines in the Baltic Sea and in the waters around Taiwan. Affected coastal States correctly complain that malign actors, like Russia and China, exploit gaps in international law that make it exceedingly challenging to hold the perpetrators accountable. None of the international agreements applicable to the protection of critical undersea infrastructure provide for adequate coastal State enf...| U.S. Naval War College Digital Commons
This article explores the rights of belligerent warships and military aircraft to engage in hostile operations within a neutral coastal State’s exclusive economic zone (EEZ) during armed conflict. It argues that peacetime rules of due regard for coastal State sovereign rights and jurisdiction do not constrain these operations. The United Nations Convention on the Law of the Sea (UNCLOS) established the peacetime obligation of due regard in the EEZ. By 1984, the EEZ had become customary inte...| International Law Studies
This article argues that there is no international legal impediment to any State robustly asserting prescriptive, enforcement, or adjudicative jurisdiction over vessels without nationality. It first examines the rules relating to vessel nationality to demonstrate the strong international preference that vessels be properly flagged in a particular State. It then examines the phenomenon of vessels without nationality, with a focus on what constitutes statelessness, and what the contemporary und...| U.S. Naval War College Digital Commons
The Southwest Atlantic lacks a regional fishery management organization, leaving one of the world’s largest squid fisheries at risk of overfishing during its high seas migrations. This article reviews measures available to coastal States as they seek to protect regional ecosystems and their economic interests. The ideal policy response is to conclude a regional fisheries management organization covering squid and other key regional stocks. This body should follow best practices and include ...| U.S. Naval War College Digital Commons
The study of underwater cultural heritage, and that of sunken warships, has typically focused on the legal protections that surround a site in the years, or often centuries, after the sinking. The Russia-Ukraine conflict has given cause to study the topic in a more modern context. Several Russian Naval vessels have been sunk by Ukraine, the most famous being the Black Sea flagship, the Moskva, in April 2022. Following the sinking, Ukraine stated the Moskva was now a heritage site, with a Ukra...| U.S. Naval War College Digital Commons
Incidents involving damage to undersea infrastructure illustrate the vulnerability of submarine cables and pipelines. While damage can occur accidentally in peacetime, recent incidents suggest cables and pipelines are being systematically targeted and that the resulting damage is not accidental or the result of poor seamanship. Most undersea infrastructure can also be attacked as a military objective in wartime. Peacetime adversaries or opposing belligerents during an armed conflict can easil...| U.S. Naval War College Digital Commons
Sea slavery—men trapped in forced labor on board illegal, unreported, and unregulated (IUU) fishing vessels—exists across the world’s oceans. If confronted with sea slavery while conducting a boarding of a foreign-flagged IUU fishing vessel on the high seas, may a coastal State military officer free the victim? This article answers the question affirmatively, relying on the duty to render assistance under the international law of the sea. That duty requires all mariners who receive info...| U.S. Naval War College Digital Commons
AI Warfare and the Law, published as a full volume of International Law Studies, analyzes the legal implications of the introduction of AI technologies into the design of weapon systems and the potential use of AI in connection with military activities. It considers several discrete but related bodies of international law as well as significant aspects of domestic and human rights law. Its key aim is to work out how the law will impact the use of AI technologies and what AI technologies must ...| U.S. Naval War College Digital Commons
In 1974, Japan and the Republic of Korea (RoK) concluded a joint development agreement concerning the continental shelf where their respective maritime claims overlapped. However, there has been no oil or gas production from the joint development zone. Therefore, after five decades of the agreement being in force, and because it can be unilaterally terminated after 2028, it is appropriate to consider what happens next for Japan and RoK in the East China Sea. Looking forward, the authors consi...| U.S. Naval War College Digital Commons
Even though eight years have passed since the issuance of the South China Sea arbitral award between the Republic of the Philippines and the People’s Republic of China, China has repeatedly claimed that the South China Sea arbitral award is null and void. Thus a question arises with regard to the legal consequences of the award in international law and international relations. The aim of this article is to consider this question by analyzing the impacts of the South China Sea arbitral award...| International Law Studies