This monograph, developed from an award-winning doctoral dissertation, offers a sophisticated analysis of overriding mandatory rules (MR) in private international law relating to international commercial contracts.

The author’s starting point is the distinction between ordinary MR, which parties can displace by choosing a foreign law, and overriding MR, which apply regardless of the parties’ choice of law or the objectively applicable law. This distinction underpins the book’s central theme: the search for a balance between contractual certainty and public regulatory interests. The author argues that overriding MR should preserve predictability for contracting parties, protect the forum state’s fundamental values, respect the legitimate interests of closely connected third countries, and promote international harmony of decisions. This normative framework – certainty, forum values, third-country interests, and harmony – guides the analysis throughout and gives the book a coherent thread running from its historical opening chapter to its arbitration-focused close.

Chapter 2 traces the doctrine’s origins and settles on “overriding mandatory rules” as the preferred term, aligning with English law and the interpretation of Article 9 of the Rome I Regulation – a choice that enhances conceptual clarity for an international readership.

One of the book’s strengths is its treatment of how overriding MR should be identified in the first place – a question of difficulty in Korea, where the Private International Law Act contains no express provision on third-country overriding MR. Chapter 3 addresses this through comparative analysis of Korean, Swiss, and EU law (the Rome Convention and Rome I), arguing that such rules may serve intertwined political, economic, social, and private interests rather than public interests alone. It proposes practical criteria – international scope, territorial reach, and the strength of a provision’s public purpose – for inferring legislative intent where the statute itself is silent.

Chapters 4 and 5 are the book’s most practically significant, standing out against its otherwise strongly theoretical register. Chapter 4 applies the Chapter 3 framework to numerous Korean statutes, showing concretely how these criteria can be used to identify overriding MR in legislation that does not expressly designate itself as such.

Chapter 5 turns to the treatment of third-country overriding MR in England, Germany, Switzerland, and the EU. The author rejects the German “factual approach” as insufficiently precise and criticises the English focus on place of performance for failing to adequately promote international harmony and uniformity, since place of performance does not always track a close connection to the dispute. Instead, the author advocates a conflict-of-laws approach grounded in close connection, arguing that it better reflects the principle of proximity and is more likely to produce internationally harmonious outcomes.

Chapter 6 builds directly on this comparative groundwork, arguing that Korean law can accommodate third-country overriding MR despite its legislative silence, and culminates in draft legislative provisions with detailed explanatory commentary – a genuine contribution to future law reform.

Chapter 7 extends the analysis to international commercial arbitration, carefully weighing the competing positions before concluding that arbitral tribunals should apply overriding MR of closely connected third countries, rather than leaving the matter to post-award refusal of recognition and enforcement.

One area that could have been developed further in the book is the CJEU’s jurisprudence on Article 9(3) of the Rome I Regulation (Greece v Nikiforidis (C-135/15) EU:C:2016:774); given its importance to the third-country question, deeper engagement with this case law would have further strengthened an already impressive comparative analysis.

Overall, this book makes an outstanding contribution to this area of law.