Why International Law?

Do domestic courts deal with legal acts that are distinctive from domestic ones when they interpret international law? Arguably not, for in some respects, the

‘divide’ between domestic and international law is anything but sharp.144 Writ-ten and unwritWrit-ten law, agreements (both private and public), custom, and gen-eral principles exist in both domestic and international law. Many sources of international law draw upon State practice. Domestic laws often mention the State’s international legal obligations, and domestic legal practices enable (or undermine) the observance of these obligations in the domestic legal order.

State organs implement both domestic and international law.145 Importantly, the respective subject matters of these two bodies of law tend to converge,146 especially due to the proliferation of ‘inward- looking’147 international legal norms governing States’ conduct within their own jurisdiction.

Because of these overlaps between domestic and international law (which scholars have captured via concepts such as ‘consubstantial norms’,148

facultas 2015); Andreas Glaser and Lorenz Langer, ‘Die Institutionalisierung der Bilateralen Verträge: Eine Herausforderung für die schweizerische Demokratie’ (2013) 23 Schweizerische Zeitschrift für internationales und europäisches Recht / Revue suisse de droit international et de droit européen 563.

143 Federal Council, Das Verhältnis von Völkerrecht und Landesrecht, Bericht des Bundesrates in Erfüllung des Postulats 07.3764 der Kommission für Rechtsfragen des Ständerates vom 16. Oktober 2007 und des Postulats 08.3765 der Staatspolitischen Kommission des Nationalrates vom 20. November 2008, 5 March 2010, fg 2010 2263 (hereinafter: Federal Council, 2010 Report on International and Domestic Law).

144 Janne E Nijman and André Nollkaemper, ‘Introduction’ in Janne E Nijman and André Nollkaemper (eds), New Perspectives on the Divide Between National and International Law (Oxford University Press 2007).

145 Jonkheer HF van Panhuys, ‘Relations and Interactions Between International and National Scenes of Law’ (1964) 112 Recueil des cours de l’Académie de droit international 7.

146 Ximena Fuentes Torrijo, ‘International Law and Domestic Law: Definitely an Odd Couple’

(2008) 77 Revista Jurídica Universidad de Puerto Rico 483.

147 Christian J Tams and Antonios Tzanakopoulos, ‘Introduction: Domestic Courts as Agents of Development of International Law’ (2013) 26 Leiden Journal of International Law 531, 534.

148 Tzanakopoulos, ‘Domestic Courts in International Law:  The International Judicial Function of National Courts’ (n 57); ila, ‘Preliminary Report of the ila Study Group on

‘multi- sourced equivalent norms’,149 or ‘interface norms’),150 it could be argued that when domestic courts interpret international law, their activity is not fun-damentally different from the interpretation of domestic law. Yet domestic laws should not be equated too hastily with international ones, as domestic and international lawmaking processes are distinct.151 While domestic laws are created by the legislature of one State (and, to a certain extent, by this State’s judicial and executive organs), international lawmaking typically involves at least two States via their organs.152 This difference determines the way inter-national law must be interpreted. For instance, one cannot solely resort to one State’s unilateral, internal practice to ascertain international law. Domestic courts must take the characteristics of international lawmaking into account.

Otherwise, they are not interpreting the interpretandum.

International law creates distinctive challenges for legal interpreters, not only because its process of formation differs from that of domestic norms, but also because it is frequently vague, as I will argue in more detail (infra, Chapter 5, 4.1.2).153 Unfortunately, and to expand on my previous remarks on the topic (supra, 2.2), legal theorists and philosophers have tended to neglect international law, with the exception, perhaps, of international human rights law.154 Detailed jurisprudential analyses of the interpretation of international

Principles on the Engagement of Domestic Courts With International Law’ (n 61); ila,

‘(Study Group on) Principles on the Engagement of Domestic Courts With International Law, Final Report:  Mapping the Engagement of Domestic Courts With International Law’ (n 15) 13. For a critique of this terminology (but not of the existence of relation-ships between domestic and international law, eg in ihrl):  Besson, ‘Human Rights’

Adjudication as Transnational Adjudication: A Peripheral Case of Domestic Courts as International Law Adjudicators’ (n 56).

149 Tomer Broude and Yuval Shany (eds), Multi- Sourced Equivalent Norms in International Law (Hart Publishing 2011).

150 Nico Krisch, ‘Pluralism in International Law and Beyond’ (2015) 8  <papers.ssrn.com/

sol3/ papers.cfm?abstract_ id=2613930>.

151 Samantha Besson, ‘Theorizing the Sources of International Law’ in Samantha Besson and John Tasioulas (eds), The Philosophy of International Law (Oxford University Press 2010) 167.

152 See also Mattias Kumm, ‘The Legitimacy of International Law:  A Constitutionalist Framework of Analysis’ (2004) 15 European Journal of International Law 907, 915.

153 On vagueness, see Hart (n 78) 124 ff. On its relationship to open texture, see Friedrich Waismann, ‘Symposium: Verifiability’ (1945) 19 Proceedings of the Aristotelian Society 119, 123; Joseph Horovitz, Law and Logic: A Critical Account of Legal Argument (Springer 1972) 9; Frederick Schauer, ‘On the Open Texture of Law’ (2011) 4 f <papers.ssrn.com/

sol3/ papers.cfm?abstract_ id=1926855>. See also infra, Chapter 5.

154 Eg Endicott, ‘“International Meaning”: Comity in Fundamental Rights Adjudication’ (n 79); Kristen Hessler, ‘Resolving Interpretive Conflicts in International Human Rights Law’

(2005) 13 Journal of Political Philosophy 29.

law are rare in canonical works of legal theory. Even scholars who have pro-vided seminal descriptive or normative accounts of the mechanics of domes-tic adjudication have often bracketed international law.155 This also applies to Swiss scholarship on domestic adjudication. As Holger Fleischer notes, ‘most literature on [legal interpretation and statutory interpretation] still treats in-terpretative methodology as a national field of study’.156 This neglect, which has a range of causes157 that I cannot fully explore here, makes it timely to devote attention to the topic.

Another important justification and trigger for analyzing domestic courts’

interpretation of international law is that this activity takes up an increasingly significant place in domestic (and Swiss)158 adjudication. This practical signif-icance is not only due to Switzerland’s growing network of treaties with other States and ios. It is also symptomatic of a shift in the subject matter of inter-national law. As is well known, this body of law is evolving from a law predom-inantly governing interstate relationships to one increasingly concerned with intrastate matters. Many other factors explain the rising significance of inter-national law in domestic and Swiss courts, such as the interinter-nationalization of judges and lawyers’ legal education, or the greater accessibility of international legal documents (see however infra, Conclusion and Recommendations, sec-tion 2). The precise weight of these causes would require empirical verificasec-tion and will not be dwelled upon here. What matters, for my purposes, is that the relevance of international law in domestic courts makes it a worthwhile and topical object of inquiry.

A last reason for focusing on international law relates to the specificities of the Swiss legal order (infra, Chapter 3), and to the impact of these features on the relationship between domestic and international law. Chief among these peculiarities are Switzerland’s semi- direct democracy (infra, Chapter 3, 3.4), coupled with recent trends in Swiss politics. In the past, popular proposals to

155 Kennedy, A Critique of Adjudication (n 78); Hart (n 78); Raz, Between Authority and Interpretation: On the Theory of Law and Practical Reason (n 78); Dworkin (n 77); Henry M Hart and Albert M Sacks, The Legal Process: Basic Problems in the Making and Application of Law (mimeographed, tentative edition 1958).

156 Holger Fleischer, ‘Comparative Approaches to the Use of Legislative History in Statutory Interpretation’ (2012) 60 American Journal of Comparative Law 401, 402.

157 This neglect may for instance be due to a lack of specialized training or interest in inter-national law, to a sense that interinter-national law is not conceptually different from domestic law or, to the contrary, to a sense that the (alleged) ‘inferiority’ of international law justi-fies analyzing it separately from domestic law.

158 Ammann, ‘International Law in Domestic Courts Through an Empirical Lens: The Swiss Federal Tribunal’s Practice of International Law in Figures’ (n 5).

amend the Swiss Constitution were rarely accepted by Swiss voters, but in the last couple of decades the success rate of these popular initiatives has risen significantly. This, and the increased targeting of international law by some political groups,159 creates tensions with Switzerland’s international obliga-tions. Because the Swiss Constitution does not offer mechanisms to arbitrate conflicts between constitutional or federal statutory law, on the one hand, and international law, on the other,160 this task is shifted to the courts. In light of the scarce guidance provided by the Constitution, Swiss courts face the chal-lenge of having to develop a predictable, clear, and consistent approach to such conflicts. Their ‘pragmatic methodological pluralism’ (infra, Chapter 3, 4.2.6), in particular, needs to be critically evaluated in the context of the in-terpretation of international law and, if necessary, adjusted to its specificities.

More generally, in a time when international law experiences heightened contestation and criticism in the domestic political realm,161 it is particularly essential that judges, international lawyers, and the public in general remain aware of the mandatory international legal framework that constrains States in the interpretation of their international obligations.