This book represents the continuation of the classic Italian treatise of international law first published by the late Mario Giuliano in two volumes in 1974 and later co-authored by Professor Giuliano, Tullio Scovazzi and Tullio Treves. After the decision of Professor Scovazzi to draw up his own textbook, Professor Treves has been left the sole author of this textbook, from which generations of Italian university students have learnt what international law is about.

As the author acknowledges at the outset (p xiv), this book is far from being a mere update of the previous editions. After a comprehensive and detailed chapter on the history and fundamental principles of international law, the subjects of international law are examined. Two observations can be made on this point. First, a whole chapter is devoted to State succession, which marks a difference with most other textbooks. Secondly, although much of the analysis is focused on the primary subjects of international law, ie States, other subjects are also discussed, such as the Holy See, the Sovereign Order of Malta and, more importantly, governments in exile, peoples, insurgents and national liberation movements (with stimulating pages on the Polisario and on the Palestine Liberation Organization). International organizations are discussed in a separate chapter, which also includes a section on non-governmental organizations. As to individuals, the author first analyses the substantial and procedural rights conferred upon them by the most important international human rights instruments, and then examines the violations of the obligations directly imposed on individuals by international law, ie international crimes. Professor Treves notes that, at the end of the day, the international rules conferring rights and duties on individuals are still created by States. Therefore, should one consider the participation in the formation of international rules to be essential to acquire legal personality, individuals cannot yet be included among the subjects of international law. On the other hand, if one considers the granting of certain rights and the imposition of certain obligations on individuals by international law to be sufficient, then individuals might be entitled to a limited international personality (pp 190–91).

In the subsequent chapters, Professor Treves critically engages in a discussion of the sources of international law. The author does not reject the doctrine of the ‘persistent objector’ but reckons that its justification lies on a temporary and limited fragmentation of the international community (pp 233–35). If a State persistently rejects a customary rule during the process of its formation, the result is a special or local custom, created by and applicable to only a specific group of States, not including the persistent objector. Another possible explanation suggested by the author is that, when one or more States have acquiesced to the persistent objector's claims, there would be a (tacit) agreement limiting the subjective scope of application of the custom. The analysis of the law of treaties covers more than one hundred pages, of which those on the effects of treaties on third States are particularly noteworthy. It is also commendable that some usually neglected sources of international law are examined: in particular, the section on unilateral acts is hardly seen in Italian international law textbooks.

The chapter on the use of force is to be found between that dealing with the law of treaties and that on the law of State responsibility, although one would have probably expected to see the jus ad bellum discussed right after Chapter XII, which is dedicated to the peaceful settlement of international disputes. A specific chapter on the use of force is a significant and important addition to the previous edition of the textbook, which only contained a few pages on this issue in the section on general trends of the international community. The author examines the most recent cases of use of force and concludes that if claims of illegality are rather weak with regard to the 1991 Gulf War and the 2001 use of force against Afghanistan, they become difficult to dismiss in the case of the 1999 Operation ‘Allied Force’ against Yugoslavia and, even more, of the 2003 Operation ‘Iraqi Freedom’. However, more than merely identifying breaches of international law or attempting to justify them, Professor Treves holds that the lawyer's task is to determine how to adapt the current norms to the new situations and values, keeping in mind that the law necessarily implies the existence of clear rules and effective mechanisms to ensure their compliance (pp 470–71).

State responsibility is dealt with in Chapter XI. The author supports the deletion of the notion of ‘international crimes’ from the 2001 International Law Commission (ILC) Articles on State Responsibility (p 504). However, he also notes that the arguments in favour of and against ‘international crimes’ also apply to the concept of ‘serious breaches of obligations under peremptory norms of general international law’ now used in the ILC Articles. Furthermore, it is hard not to agree with Professor Treves when he questions the feasibility and opportunity of introducing a distinction between serious and non-serious violations of jus cogens rules: indeed, it appears that seriousness characterizes by definition any violation of such fundamental and intransgressible norms.

The last chapter is dedicated to the implementation of international law in the Italian legal order and is without any doubt one of the highlights of the book. Some sections have been completely re-written to take into account Constitutional Law no 3 of 18 October 2001, which amended Article 117 of the Italian Constitution. There is controversy over whether the new version of this provision really confers constitutional rank in the hierarchy of Italian legal sources to treaties ratified by Italy. Professor Treves agrees with those who argue that no significant changes to the system of sources have been introduced by Law no 3/2001 and that constitutional challenges to national laws based on Article 117 (1) of the Constitution should be exceptional (pp 694–95).

Professor Treves's experience as a judge of the International Tribunal for the Law of the Sea since 1996 emerges throughout the work, where frequent references to the case law of the Tribunal and a detailed section devoted to its composition and functioning stimulate the student to get acquainted with the law of the sea. Furthermore, the author's references to primary sources, often extensively quoted, make the textbook's approach refreshingly pragmatic. The indexes are detailed and useful, and so is the initial bibliographical note. The extensive footnote apparatus containing references to relevant literature and the final table of cases are also praiseworthy. However, a table of treaties and of national legislation probably would have been helpful for the reader.

To conclude, Professor Treves's treatise is a very learned but also very easily readable book that Italian-speaking students, academics and practitioners will not fail to appreciate. It is this reviewer's hope that an edition in English will make it accessible to a broader readership.