International law, perhaps more than any other branch of the science, is progressive. In its study, the elements of this progress should be traced to their origin. International law has been a growth of mutual understanding between nations, developed out of necessities of particular situations, ripening gradually from precedent to precedent and finally formulated and codified in international conventions and treaties. Of these the most notable are the conventions adopted at the two conferences held at The Hague in 1899 and 1907.

It is not surprising to find that times of war have given rise to many of the rules which nations have gradually come to recognize and embodied in the system which has become common to them all. In times of peace the situation adapts itself more readily to the requirements of each nation. War necessarily displaces the ordinary course of business and human conduct.

Customary international law often seems like a riddle wrapped in a mystery inside an enigma. According to Manley O. Hudson, even the drafters of the International Court of Justice Statute “had no very clear idea as to what constituted international custom.” The situation has not changed much since then.

I got my first taste of the difficulties in identifying custom when I was a junior attorney at the U.S. Department of State and was assigned the task of preparing the U.S. submission in a juvenile death penalty case before the Inter-American Commission on Human Rights. The juvenile death penalty is prohibited by the International Covenant on Civil and Political Rights (ICCPR) and the American Convention on Human Rights, but the question in the Inter-American Commission case was whether it is also prohibited as a matter of customary international law.

The field of global migration law looks beyond international law to incorporate all levels of the law, including the regional. This essay explores the regional regulation of mobility, which has indeed become a central subject of discussion and academic analysis. The expansion of human rights law coupled with the explosion of regional processes of integration are the two most important phenomena that have limited the state's capacity to restrict the entry of foreigners and their rights. It should come as no surprise that regional agreements facilitating mobility have proliferated and now involve around 120 countries, either at a bilateral or multilateral level. For one thing, most global migration is regional, whether in Europe, Africa, Asia, or Southern and Central America. In addition, regional instruments can be agreed on more rapidly and, in principle, introduce higher standards of protection and rights due to the more limited number of actors involved in the negotiations. There is, of course, huge variation across regions as to the degree of development of the various agreements, the categories of individuals entitled to mobility and equal treatment and their effective application and enforcement mechanism devices.

The Sykes–Picot agreement embodies a certain style of diplomacy: an assumption of European predominance, given expression through cartographic line-drawing, terms of art (“protection,” “independence,” “interests”), and a structural secrecy which kept agreements from rival European powers, on the one hand, and from the peoples most affected, on the other. It is this element of secrecy that constitutes the focus of the present contribution. I situate the Sykes–Picot agreement in a prewar pattern of secrecy as diplomatic technique, explore its role in spurring a new regime of publicity for treaties, and take it as a touchstone for exploring whether this new regime could achieve a fundamental transformation of prevailing modes of diplomacy.

On November 30, 2016, after much uncertainty, the Colombian Congress finally approved a historic peace deal between the Colombian government and the Fuerzas Armadas Revolucionarias de Colombia (FARC), bringing to an end the country's fifty-year conflict. This peace deal was a historical achievement, and had important ramifications for international law, as discussed in a recent AJIL Unbound symposium. But once the spotlights were off, the government was faced with the daunting challenge of implementing the complex, lengthy accord. In particular, the government had to draw up and pass through Congress the legal and constitutional framework for the transitional justice process—a key component of the peace deal. It is there, in the subtle details of domestic criminal law, where the balance between peace and justice must be achieved.

Sara Mitchell and Andrew Owsiak's examination of the impact of UN Convention on the Law of the Sea (UNCLOS) and Article 287 declarations on the peaceful resolution of maritime disputes significantly advances the literature on the relationship between international law/international courts and maritime issues. To their credit, the authors employ a wide range of empirical tests in the article to provide readers with confidence in the empirical results. Nonetheless, there are some important limitations in their approach. Drawing on insights from the causal inference literature, I argue that Mitchell and Owsiak's empirical analyses suffer from two biases that both (1) raise concerns about the causal relationships identified in the article, and (2) suggest some important scope conditions in its empirical findings. I investigate the biases and propose suggestions for legal scholarship to produce more credible results.

A landmark of the law of naturalization in the United States, established by the Supreme Court after a tortuous course of decision, has now found legislative confirmation in a provision in the Internal Security Act of 1950.

The oath of petitioners for naturalization provided for in §4 (3) of the Act of 1906 required a declaration of willingness “to support the Constitution and laws of the United States against all enemies, foreign and domestic, and bear true faith and allegiance to the same”; and the Act provided that the naturalization court must be satisfied that during his residence the petitioner has behaved as a man “attached to the principles of the Constitution of the United States, and well disposed to the good order and happiness of the same.”

For some years the question was put to petitioners, “If necessary, are you willing to take up arms in defense of this country?” A negative answer to this question led to a denial of the petition in U. S. v. Schwimmer (1929), 279 U. S. 644. This was followed in U. S. v. Macintosh (1931), 283 U. S. 589, and U. S. v. Bland (1931), 283 U. S. 636. Despite these decisions, no change was made in the required oath when the Nationality Act was revised in 1940. Yet the three earlier decisions were overruled in U. S. v. Girouard (1946), 328 U. S. 61, on the ground that the required oath might properly be taken by a person unwilling on religious grounds to bear arms.

Recognition is a formal expression by its author about how she perceives the situation to which recognition is extended. Recognition simultaneously constitutes a means for its author to make known her own view of a situation, including the legal consequences, if any, that the author attributes to the situation, and on which the author intends to base her policy. Albeit a political act, recognition deeply affects the international legal system and carries wide-ranging legal effects in both the international and domestic legal orders, especially when it comes to the recognition of states and governments.