In the intricate tapestry of public international law, a discerning thread emerges that binds together several seemingly disparate domains: international criminal law (ICL), human rights and international human rights law (IHRL), customary international law, and diplomacy. At the heart of this unifying element lies the foundational principle of accountability and the pursuit of justice on the global stage. ICL, as embodied in the Rome Statute and its jurisprudential evolution, seeks to hold individuals accountable for the gravest international crimes, thus underscoring the international community's commitment to the (international) rule of law. Simultaneously, IHRL endeavours to protect the inherent dignity and rights of individuals worldwide, ensuring that the principles of justice and fairness transcend borders. Customary international law, an ever-evolving body shaped by state practice and opinio juris, reflects the shared sense of obligation among states to adhere to certain norms and customs rooted in the pursuit of justice. Diplomacy, the quintessential tool of statesmanship, facilitates dialogue and negotiation, fostering peaceful resolution of conflicts and enabling the realization of justice through international agreements and treaties. As this review essay delves deeper into these interconnected spheres, it will scrutinize the nuances and interplay among these realms of international law, exploring the dynamic relationships, tensions, and synergies that shape our contemporary global legal landscape. To illuminate these connections, the reviewer engages with three seminal monographs, each meticulously examining a distinct facet of this multifaceted prism: one analyzing the complicated intersection of human rights and ICL, another one delving into the symbiotic relationship between IHRL and diplomacy, and the third one offering a focused analysis of the Rome Statute as a crucial document reflecting customary international law, thereby laying the groundwork for a comprehensive comparative exploration of these vital areas of international legal scholarship.

The first book, Human Rights and International Criminal Law, scrutinizes the importance of ICL in promoting and defending human rights as well as ICL's relationship with law and international politics. Using the relevant jurisprudence of key international criminal justice systems such as International Criminal Tribunals for the former Yugoslavia and Rwanda and the International Criminal Court (ICC), the book copes with its task by way of structuring the text along three main key themes: human rights approaches to crimes (Chapters 1–3); the crimes proper (Chapters 4–10); and practice, application, implementation, and enforcement (Chapters 11–17). Authored by notable scholars from America, Asia, and Europe and edited by respected international law professors, the book's chapters convincingly demonstrate how issues of state and individual responsibility for mass violations of human rights correlate at both substantive and procedural levels and ponder on challenges caused by that correlation for the modern system of international criminal justice; for example, by discussing the victims’ role at the ICC and the right to truth. This is important because, as the reviewer's teaching experience also reveals, modern students, lawyers, and scholars often confuse the two legal regimes of ICL and human rights law or mistakenly perceive them as mutually exclusive, which is far from the truth. Another important issue considered in this volume is why certain types of human rights violations, such as human trafficking and terrorism, have not yet been included in the list of core crimes of the Rome Statute. The book offers a solid academic treatment of these and many other relevant matters related to the interplay between ICL and human rights.

The second book, International Human Rights Law and Diplomacy, by Kittichaisaree, an author with relevant academic (professor) and practical (former ambassador and international judge) experience, constitutes a unique scrutiny of how the IHRL works in the real world. It provides a comprehensive overview of how human rights protection systems operate (or otherwise) at both universal (United Nations) and regional levels (all geographical regions of the world) and looks at IHRL treaty obligations within the example of major human rights treaty instruments. Topical issues of contemporary IHRL, such as human rights universalism, cultural relativism, allegations of hypocrisy, and double standards applied by nations (states), are tackled, as are the diplomatic methods that have been employed for the purposes of eluding their respective human rights obligations. Despite its announced title, a laudable aspect of the book is that human rights are treated first as a legal concept, not merely a political or cultural phenomenon, and that they work and function only within the parameters of the law, not outside of its purview. Furthermore, this work incorporates a rather realistic view of the modern system of international obligations of states based on a background understanding of a long-known fact: international law has been reliant, since its Westphalian roots were established, upon the political will of states thanks to the all-dominating notion of state sovereignty serving national interests and not individual needs. This reviewer believes that the book could benefit even more from a greater conceptual treatment of diplomacy as an essential tool of international negotiation and the proper conduct of states. When it appears that public international law is thought of as being in deep crisis and diplomacy is often shrugged off as weak and/or inefficient, demonstrating how the latter could employ its potential to help deal with human rights problems could be instrumental. In any case, International Human Rights Law and Diplomacy represents an outstanding and novel contribution to the existing scholarly literature.

The third book, The Rome Statute as Evidence of Customary International Law, by Yudan Tan of Leiden University, brings in another crucial element of the discerning thread mentioned above: customary international law. The author focuses well on some key substantive as well as procedural provisions of the Rome Statute, a crucial instrument of the modern international criminal justice system, such as war crimes in non-international armed conflict (Chapter 3), crimes against humanity (Chapter 4), the crime of aggression (Chapter 5), indirect co-perpetration (Chapter 6), and an exception for personal immunity for international crimes (Chapter 7). She uses the so-called “two-element customary law identification” approach (looking at both state practice and, especially, opinio juris). Books like this are important since they help clarify an often ambiguous relationship between treaty law and custom and their proper application and the interpretation of the “right” sources of international law to ICL issues. Tan's conclusion, for example, on crimes against humanity (pp. 187–8, arguing that some key aspects of Article 7 of the Statute already reflect customary law) is illustrative of that interpretation.

In summary, this review essay has underscored the existing synergies and coherence among ICL, human rights/IHRL, customary international law, and diplomacy, as illuminated by the abovementioned monographs. These volumes collectively reinforce the paramount values of accountability, justice, and the rule of law within the scope of public international law. Their positive analysis enriches scholarly discourse and holds useful, practical implications for their diverse audiences. Scholars and practitioners alike are offered a quality roadmap to navigate the sophisticated intersections of these domains, facilitating both the progressive development of international legal norms and the realization of justice on the global stage. Thus, these books serve as notable guides, contributing to the academic canon and actively shaping the practice and discourse of public international law, reaffirming its commitment to the enduring values that form the bedrock of our international community.