“Domestic Application of International Law: Focusing on Direct Applicability” by Judge Yuji Iwasawa
By Sinh Vuong Nguyen and Sarah Lorgan-Khanyile
Yuji Iwasawa’s “Domestic Application of International Law: Focusing on Direct Applicability” provides a timely elaboration on how to navigate the rapidly evolving landscape of international law. Iwasawa argues that tectonic shifts in international law have been prompted by the increased interconnectedness of States and the changing role of treaties. Where treaties once centered on the relations between States, they now increasingly center on the relations between States and individuals. As Iwasawa suggests, international law, now more than ever, reaches into the private lives of individuals. In light of these changes, he embarks on a “comprehensive study on the domestic applicability” of the rules of international law, focusing primarily on private international law. Elaborating on his previous doctrinal scholarship, Iwasawa attempts, in our view with great success, to “reconstruct the theory of direct applicability and put forward a renewed framework of analysis.”
Iwasawa articulates a crucial distinction between the direct applicability and the domestic legal effect of the rules of international law.[ii] According to Iwasawa, direct applicability concerns whether a rule of international law is “susceptible of being applied [domestically] without further measures.”[iii] In contrast, domestic legal effect is the binding legal effect (or lack thereof) of a rule of international law under the domestic legal system. Iwasawa mobilizes this distinction to argue that many courts are wrong to have concluded that direct applicability is a prerequisite to a rule of international law having domestic legal effect. The correct position, he posits, should be the opposite: domestic legal effect is the precursor to direct applicability.[iv] We agree. Direct applicability is a phenomenon occurring at the domestic level. In that regard, a state can only apply that which has already acquired the force of law. Further, the argument that only rules classified as directly applicable on the international plane may acquire domestic legal force is tantamount to a prohibition on the domestic application of rules classified on the international plane as not directly applicable. There is no evidence that such a prohibition exists under international law.
Iwasawa concludes that direct applicability is a question to be determined under domestic law. His argument is straightforward: “Since the legal force and rank of international law in domestic law are determined by domestic law, it is logical to conclude that the direct applicability of international law is also determined by domestic law.”[v] Admittedly, under his own conception, direct applicability and domestic legal effect are qualitatively different concepts. To that extent, just because domestic legal effect is decided by domestic law does not automatically mean that direct applicability must likewise be a matter decided by domestic law. Iwasawa’s argument is nevertheless defensible when considered from the perspective of private international law. The direct applicability of a rule of international law is a legal issue. Whether international law or domestic law decides the question of direct applicability is a question of the relevant choice of law to decide a legal issue. It is a truism that the forum state decides its own choice of law rules. Put differently, the forum state decides for itself whether domestic law or international law applies to decide the question of direct applicability. We submit that this is the proper basis for explaining why direct applicability is a question to be decided by domestic law. For completeness, we note that it is theoretically not impossible for the forum state’s choice of law rules to decide that international law decides the question of direct applicability, but even then, reliance on international law is justified through domestic law.
Iwasawa’s conclusion—that direct applicability is a matter to be decided under domestic and not international law—demands immediate reconsideration of the argument that the direct applicability of a treaty is governed by that particular treaty.[vi] Using the example of human rights treaties, Iwasawa forcefully argues that the question of direct applicability cannot be divined from these treaties.[vii] Here, Iwasawa’s expertise in international human rights law shines through.[viii] First, using human rights treaties to ascertain directives on the direct applicability of human rights obligations presupposes that the parties to human rights treaties have “intended” for human rights obligations to be directly applicable. But treaty parties are not very interested in the mechanisms of domestic implementation of human rights treaties; this is why all of the leading human rights instruments come with domestic implementation clauses. To that end, we find most persuasive Iwasawa’s warning that any inferred intention of the parties would be “in most cases purely fictitious.”[ix] Second, direct applicability, if understood abstractly, ignores the reality of the varied constitutional structures of states, and the reality that a treaty provision may be directly applicable in one state but not another.[x]
For all of Iwasawa’s achievements, his theoretical framework leaves a few open questions for future scholarship:
First, Iwasawa’s definition of direct applicability as “susceptible of being applied without further measures” remains unclear in terms of the juridical consequences that follow when a legal rule is applied. The paradigmatic example of directly applicable international law is a rule of international law which creates judicially enforceable individual rights in domestic law,[xi] but Iwasawa also suggests that a rule of international law can also be applied by domestic courts and administrative authorities without there being any individual rights created, for instance, as a defense to a legal claim.[xii] Because the direct application of a rule of international law may find manifestation in manifold instances, it is, in our view, a missed opportunity to define an underlying thread tying these manifold instances together.
Second, Iwasawa’s definition of direct applicability runs into some difficulty in the context of dualist systems. Having argued that domestic legal effect is a prerequisite to direct applicability, Iwasawa nevertheless argues that questions of direct applicability are still relevant in dualist systems under the logic that once “the text of the treaty is given the force of law, the question arises as to whether a provision of that treaty can be directly applied without the need for further measures.”[xiii] One could be forgiven for taking the view that, since dualist systems first require the incorporation of international law into the domestic legal system, it must follow that such incorporation amounts to a “further measure” rendering direct applicability a fortiori impossible. It is unfortunate that Iwasawa did not explain this incongruence in greater detail.
Third, Iwasawa’s thesis that direct applicability is a matter governed by domestic law runs into some difficulties in the field of EU law. It is well-settled by the Court of Justice of the European Union (CJEU) that the direct applicability of EU law is governed by EU law itself.[xiv] To that end, Iwasawa’s argument that “the concept of direct applicability is not fundamentally different in international law and EU law”[xv] conflicts with the CJEU’s case law. At the same time that Iwasawa accepts that “the legal force, direct applicability, and rank of EU law in domestic law are all determined by EU law”, he concludes that “[t]he legal force, direct applicability, and rank of international law in domestic law are thus determined by the domestic law of each State.”[xvi] Iwasawa’s positions can be reasonably reconciled in that the direct applicability of EU law is a sui generis exception from the direct applicability of international law generally speaking. But if an exception was intended, it would have been most helpful for more explanation on the rationale underlying it.
Iwasawa’s monograph is, in conclusion, a laudable effort to bring coherence and analytical rigor to a technical, difficult, and practically significant intersection between private and public international law. In thoroughly articulating the law behind domestic governance of direct applicability in international law, Iwasawa offers a rich framework to scholars and practitioners alike. Promising to influence future scholarship on the topic, the monograph invites further consideration of direct applicability and analyses of domestic governance of direct applicability as opposed to approaches of nonconforming systems (like the EU).
Yuji Iwasawa, Domestic Application of International Law: Focusing on Direct Applicability, ix (Brill Nijhoff, 2022) [hereinafter “Monograph”]. Please find the book available here.
[ii] Id. at 148–50.
[iii] Id. at 146.
[iv] Id. at 154.
[v] Id. at 162.
[vi] Id. at 47–48.
[vii] See discussion infra id. at chapters 2.B.1.–2.B.6.
[viii] Judge Iwasawa previously served as Head of the Human Rights Committee.
[ix] Monograph at 48.
[x] Id.
[xi] Id. at 154.
[xii] Id. at 157–58.
[xiii] Id. at 7.
[xiv] Id. at 96.
[xv] Id. at 139, 141.
[xvi] Id. at 162.
