1.  The domain of foreign affairs is referred to in constitutional law and its scholarship in order to demarcate the conduct of the foreign relations of a state from other, at first sight internal, matters. The idea that the conduct of foreign relations entails the requirement for a different set of rules, as opposed to the ‘regular’ affairs of a state, is rooted in a long intellectual tradition dating back to, among others, John Locke and his concept of the ‘federative power’. Likewise, the idea of a brutal state of nature in which individuals would find themselves without the security afforded by the organizing power of the stateas was powerfully sketched by Thomas Hobbes in Leviathanhas contributed to the entrenchment of the idea that constitutional democracies also need to distinguish between those affairs in which constitutionalism fully takes hold, and those relating to the external side of the state, where modifications are required for the sake of interests pertaining to national security. Quite frequently, these modifications are sought in a greater role of the executive power as opposed to the legislative and judicial branches of government. This idea can also be traced back to Locke, who held that, as such, the executive and the federative power would be separate. In practice, however, they would almost always be identical (Locke, sections 147 and 148). It is Locke, too, whose thinking is at the root of the idea that different rules govern the external side of state conduct. As opposed to the executive power, the federative power would be ‘much less capable to be directed by antecedent, standing, positive laws’. In contrast, the ‘[p]rudence and [w]isdom’ of those in power would need to be relied on in order to attain the ‘publick good’ (sic) (Locke, section 147). Quite similar considerations can be found in the opinion of Justice Sutherland in the United States v Curtiss-Wright Export Corp. decision from 1936, which is a cornerstone of the position that the external domain is governed by different rules than the internal sphere of the state: ‘the federal power over external affairs [is] in origin and essential character different from that over internal affairs’ (United States v Curtiss-Wright Export Corp (1936) 319 (US)).

2.  In many constitutional systems, the contemporary law of foreign affairs focuses on three main sets of questions, which require further analysis in this entry: (1) the separation of powers in this domain; (2) the respect for individual rights in situations in which the conduct of foreign relations is also at stake; and (3) the intensifying debate on the relationship between foreign affairs and domestic ideals of democracy and of the rule of law.

3.  While the idea of a necessarily greater role of the executive—and alongside it, a diminished role of the other branches of government—remains a staple in constitutional law discourse across a wide variety of jurisdictions, it has also come under pressure. In particular, the view that internal and external forms of state action can be clearly differentiated is no longer easily sustainable (Henkin 6). Due to the expanding scope and horizons of both public international law and also, in the context of the Member States of the European Union (EU), EU law, there has been a growing number of situations when ‘the international’ and ‘the domestic’ have become closely intertwined. While the current rise of populist movements and their criticism of international law and globalization prompts the question as to whether this development has reached its apogee or whether we may even begin to see a reversal, it still holds true that it is no longer possible to neatly distinguish between a sphere of international affairs—belonging to so-called ‘high politics’—and a sphere of purely domestic concerns.

4.  Recent debates about the conclusion of so-called ‘mega-regionals’, such as the Comprehensive Economic and Trade Agreement between Canada and the EU (CETA (signed 30 October 2016) [2017] OJ L11/23), the signed—but for the time being doomed—Trans-Pacific Partnership (TPP), and the aborted Transatlantic Trade and Investment Partnership (TTIP) underline how deeply ‘the international’ is penetrating domestic legal orders. This has also sharpened awareness of the impact of international cooperation on domestic constitutional principles such as democracy and the rule of law. For a long time, these concerns were largely external to the constitutionalist debate on foreign affairs. The foreign relations law of a number of jurisdictions is thus in a process of ‘democratization’in the sense that the primary concerns and sensibilities of this area of the law are no longer confined to question of the separation of powers (Verdier and Versteeg 514). At the same time, it should be noted that such a ‘democratization’ can occur for very different reasons. In some instances, it might lead to a convergence between the internal and external dimensions of democracy, but this is not necessarily the case. It is conceivable, for instance, that a state could engage in the promotion of democracy abroad without necessarily implementing this agenda faithfully in its internal sphere.

5.  The realities of international intercourse also impact on individuals and their rights. States frequently cooperate with each other, often for beneficial purposes. Indeed, some constitutional systems actively require states to be open for international cooperation (for instance Germany and South Africa, see Schorkopf s 1, paras 54–57, and Tladi 136, respectively). The question, then, is how to gauge the effects of such cooperation on the protection of individual rights.

6.  Every endeavour in comparative constitutional law needs to justify the criteria according to which jurisdictions have been selected for discussion. What is more, the way research questions are framed may also lead to an exclusion of constitutional systems in which these questions are not askedor in which they are asked in such a different way that it becomes difficult to draw comparisons. The main questions identified for this entry have a strong resonance with constitutionalist systems which are organized according to some form of the separation of powers. What is more, the questions pertaining to democracy and the rule of law also exclude the consideration of jurisdictions in which these constitutional ideals are not embodied. Hence, there is a strong risk to fall into the trap of a self-referential, liberal, and Western mindset which takes discussions in a few jurisdictions of the ‘Global North’ as being representative of the broader global picture. The risks pertaining to this selection bias are flagged so that the reader can draw his or her own conclusions. At the same time, the debate about the limits of international cooperation flowing from democracy and the rule of law is also mimicked in jurisdictions many would not consider to be liberal democracies. In some cases, there is evidence of an unexpected form of learning process.

7.  In addition, there is another reason for the focus of this contribution on certain jurisdictions from the ‘Global North’. From a survey of the existing literature, it appears that a proper academic sub-discipline of ‘foreign relations law’ has only emerged in a limited number of jurisdictions. These are, first of all, the United States (US), the United Kingdom (UK) (with the addition of a number of other Commonwealth and Common Law jurisdictions), France, and Germany. There is also a substantive body of literature on the foreign relations law of the EU. Yet, even in the typical list of candidates for expansion of comparative law scholarship beyond this circle—such as India, Israel, and South Africa—to the knowledge of this author there exist no specialized treatises or monographs devoted to this field. While this entry is not the right place to remedy this deficit, wherever possible the discussion will also draw on constitutional provisions, case law, and contributions from the literature pertaining to these jurisdictions. Looking beyond this entry, it is certainly a desideratum to see more scholarship develop about the foreign relations law of jurisdictions from non-Western states. In any case, the prevailing focus on a number of Western jurisdictions in this field is also an example of the power dynamics with respect to the production of scholarly knowledge. Key categories for academic debate are developed against the background of specific jurisdictions, with their at times quite idiosyncratic institutional set-ups and developments. This holds true, in particular, for the foreign relations law of the US. The academic debate on US law in this area is highly influential for the global academic community. Yet, very few systems actually borrow from the US experience, at least not directly.

8.  The topic of this entry also needs delimitation from other questions. In constitutional law terms, the entry ‘foreign affairs’ translates most easily into the category of ‘foreign relations law’. This notion is usually understood to refer to all those constitutional rules which are meant to determine the conduct of foreign relations of a given state—ie its participation in forms of traditional diplomacy and forms of cooperation in the context of international and supranational organizations. It also relates to the respective roles of different organs of states in international law-making processes—ie the question of the treaty-making power, or which organ of state is entitled to express the opinio iuris of the state for the sake of the formation of customary international law. Beyond these questions, there is debate on the contours of this field of law. Whereas some count questions pertaining to the status of international law—and EU law—to be part of the field of foreign relations law (Henkin 198), others exclude them as they refer to the interaction of different fields of the law (Giegerich para. 3). The divergent views on this matter may have something to do with broader conceptual choices relating to the relationship between international and domestic law.

9.  The long-established and somewhat exhausted debate about dualism / monism as organizing principles for the relationship between international and domestic law may no longer adequately express the varieties of law in all of its contemporary complexities (von Bogdandy 397). Yet, the categories linger on as basic organizing principles to conceptualize the interplay of law from different sources. Those who lean more towards a monist understanding of the relationship between international and domestic law are disinclined to view the domestic constitutional law rules on the status of international law as part of the field of ‘foreign relations law’. According to this perspective, this view resembles the tradition of this notion in both German and US American constitutional law, where it was often used as a kind of Ersatz international law, although one which is firmly rooted in the domestic legal order (critical in this regard is McLachlan (2014) 1.30). In contrast, authors who follow a more traditional, dualist framework would have no problems in understanding the ‘Supremacy Clause’ of the US Constitution (Constitution of the United States of America: 17 September 1787 (as Amended to 7 May 1992) Art. VI, Clause 2 (US)) or Arts 25 and 59 of the German Basic Law (Basic Law of the Federal Republic of Germany: 23 May 1949 (as Amended to 23 December 2014) (Ger)) as parts of the ‘foreign relations law’ of the respective system, since in their view it must ultimately be the domestic legal system which determines the status of international law (Schorkopf section 3, para. 1).

10.  Regardless of this debate about the scope of ‘foreign relations law’, it is important to uphold a clear distinction between the rules of public international law proper and the domestic constitutional law of a given system. ‘Foreign relations law’ is domestic law. From a doctrinal perspective it cannot be framed as a replacement of international law, and from a policy perspective it should not, because otherwise the integrity and independence of international law would be endangered.

11.  This does not stand in the way of linking the study of foreign relations law with the nascent stream of literature engaging in so-called ‘comparative international law’ (Koskenniemi 1; Roberts 57). Authors engaged in this project study the specificities of how international law is made, shaped, and applied in various domestic situations (Roberts, Stephan, Verdier, and Versteeg 469). They thus aim at contextualizing the workings of international law. For this endeavour, the respective foreign relations law of domestic constitutional systems can yield valuable insights, since different approaches towards international law will, in many situations, be conditioned by domestic constitutional systems. Conversely, the study of foreign relations law will benefit from a comparative perspective on how international law is introduced into different legal systems, thereby contributing to a questioning of orthodox views within the respective legal system.

12.  More generally, foreign relations law need not be limited to constitutional law. It can also be based on statutory law, administrative regulations, and other legal sources. The concrete conduct of a state’s foreign affairs can often be owed to a complex interplay of different legal sources. What is more, the conduct of the foreign affairs of a given state is, of course, also influenced by political considerations which may limit the recourse to certain options a given constitutional system might provide for. It can even be asked whether foreign relations law is more strongly affected by political considerations than other branches of constitutional law. Asking this question takes us back to the starting point of this entry, ie the question of whether the external sphere of states is necessarily subject to different rules than the internal sphere. However, while the conduct of foreign affairs is necessarily a politically charged endeavour, this should not lead to a simplistic and binary view which understands domestic affairs as less political in comparison. Rather, the specificities of the conduct of foreign affairs relate to the fact that, in foreign affairs, the conduct of other political actors also needs to be accounted for. It is not just the domestic political process which impacts on constitutional law, but rather a combination of various factors and external forces which may make the application of the law less predictable and will, in turn, also limit the available policy options for many actors.

13.  The conduct of the foreign affairs of a state has traditionally been seen as a matter for the executive. This is sometimes expressed directly in constitutional provisions (see, for instance, Art. 73 of the Constitution of Japan: 3 November 1946 (Japan); Art. 89, para. X of the Political Constitution of the United Mexican States: 5 February 1917 (as Amended to 29 July 2010) (Mex)). More often, it is assumed from reading between the lines of constitutional provisions (Henkin 33), or has been deduced from functional arguments. As an early authority on foreign relations law put it: ‘[t]he legislative body is usually large, slow moving and ill-informed on foreign relations’ (Wright 7). Pronouncements to that effect can also be found in contemporary court decisions. In a recent case on the recognition of states and the respective domestic competences in that regard, Justice Kennedy formulated, in the opinion of the Supreme Court of the United States, that recognition is a topic on which the nation ‘must speak with one voice’, relying also on earlier case law (Zivotofsky v Kerry (2015) 11 (US)).

14.  In practice, however, the picture today is much more nuanced, and most constitutional systems give the legislative some role in the conduct of foreign affairs. This becomes most noticeable in treaty-making processes (see, for example, Art. 53-1 of the Constitution of the French Republic: 28 September 1958 (as Amended to 23 July 2008) (Fr); Art. 59, para. 2 of the German Basic Law (Ger); Art. 61 of the Constitution of Japan; Arts 245 and 246 of the Constitution of the Republic of India: 26 January 1950 (as Amended to 28 May 2015) (India) in connection with List I in the Seventh Schedule; Art. 76, para. 1 of the Political Constitution of the United Mexican States: 5 February 1917 (as Amended to 29 July 2010) (Mex); Art. 231, para. 2 of the Constitution of the Republic of South Africa: 11 October 1996 (as Amended to 1 February 2013) (S Afr)). In some strictly dualist systems, such as the UK, India, or Israel, the legislative is not involved in treaty-making processes. This is justified on the basis of the absence of any legal effect of international agreements which have not been transformed into domestic legislation (on the UK see McLachlan (2014) 5.09; on India Kanwar 241; on Israel Kretzmer 281–82—also on the practice to table international agreements in the Knesset two weeks before ratification). At the international level, it is usually the executive which expresses a given state’s consent to be bound by an international agreement. However, international law also implicitly recognizes that states may wish to opt for a combined procedure involving the participation of other domestic organs, most often parliaments (Art. 14 of the Vienna Convention on the Law of Treaties (1969) (concluded 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331). If recourse to a combined form of treaty-making takes place, the participation of parliament may authorize the executive to ratify the treaty on the international level. Domestically, the participation of parliaments can also fulfil the function to incorporate or transform an international agreement into domestic law and secure the democratic legitimacy of the agreement.

15.  Despite the participation of the legislative, in many systems the executive continues to enjoy considerable discretion with respect to the negotiation process. Most often, the legislative is then faced with the option to accept or reject a given treaty. It is precisely this privileged position of the executive which has recently come under heightened scrutiny. In the context of the negotiation of the aforementioned ‘mega-regionals’, critics have pointed to the law-making function of these agreements, and have insisted that parliaments and the general public should be involved at an earlier stage so as to have a real possibility to influence the negotiation of these agreements (see further von Arnauld 268–282). While the negotiation practice of the EU has reacted to these demands favourably, at least in some respects, other participants continue to be sceptical towards such demands.

16.  Since the legislative is involved in treaty-making process, it can also conceivably play a role in the termination of international agreements (see, for instance, Art. 76, para. I of the Political Constitution of the United Mexican States: 5 February 1917 (as Amended to 29 July 2010) (Mex)). In this context, it is noteworthy that there seems to be no general rule of participation of the legislature in the termination process, which would be comparable to the assessment that, typically, parliaments are involved in the treaty-making process. Especially in dualist systems, the argument is made that a decision of the executive to withdraw from an international agreement does not affect the internal law of that state. This is only seemingly contradicted by recent case law from the UK, in the context of the preparations for the so-called ‘Brexit’ under Article 50 of the Treaty on European Union (TEU). The decisions of the British courts on that matter, first of the High Court, then of the Supreme Court, called for a participation of Parliament due to the specifics of European integration. As the European treaties would have provided for individual rights irrespective of further implementing legislation, the filing of the declaration of the government under Art. 50 TEU could conceivably lead to the automatic cancellation of these rights (R v Secretary of State for Exiting the European Union (2017) (UK)). It is noticeable, however, that the politics of treaty termination have also become more controversial beyond the ‘Brexit’ debate (see Lange). In constrast to the UK Supreme Court, the North Gauteng High Court in South Africa has recently taken a more principled approach to the question of parliamentary participation in treaty withdrawals, in a case concerning withdrawal from the Rome Statute of the International Criminal Court ((adopted 17 July 1998, entered into force 1 July 2002) 2187 UNTS 90). Arguing that Article 231 of the South African Constitution requires parliamentary approval for the conclusion of treaties, the North Gauteng High Court relied on an ‘a contrario’ approach, and deduced from the provision that the same requirement would apply for treaty termination (Democratic Alliance v Minister of International Relations and Cooperation and Others (2017) (S Afr)).

17.  The special role of the executive has also been invoked in order to limit judicial control over the conduct of foreign affairs (executive privilege). In this regard, courts in various jurisdictions have developed so-called ‘avoidance doctrines’, which come under different names (Benvenisti 161). These doctrines range from a ‘political questions doctrine’ (Baker v Carr (1962) (US)) over the figure of the ‘act of state’ (Banco Nacional de Cuba v Sabbatino (1964) (US)), to a more general willingness to pay ‘deference’ to the executive in matters of foreign affairs (judicial deference). Yet, the finding thatin the USa ‘foreign affairs exceptionalism’ is most prevalent in this field (Bradley (1999) 1104–1107) has also been contested and contrasted with a ‘normalization’ in foreign relations law (Sitaraman and Wuerth 1902–1903).

18.  In other jurisdictions, similar debates have played out, yet there is also wide-ranging scepticism as to whether the foreign affairs factor limits the judiciary’s control vis-à-vis acts of other branches, primarily the executive. In the UK, for instance, the royal prerogative did in the past lead to similar considerations as ‘deference to the executive’ in the US (McLachlan (2014) 1.37). In the UK, the idea that the executive enjoys some special privileges in a foreign affairs context continues to enjoy some support. At the same time, this has come under pressure through the enactment of the Human Rights Act in 1998. For Israel, it has been noted that, although the courts would have never adopted a doctrine of deference in the proper sense of the word, for quite some time the interpretation of the executive with respect to the occupied territories had been adopted by the courts (although the practice has changed over time, see Kretzmer 292). In other dualist systems, such as in South Africa, the question of deference is avoided by the strict demarcation between an international agreementwhich does not form part of the domestic legal orderand an incorporated treaty. Whereas courts would probably follow an executive interpretation with respect to an international agreement, the same would not necessarily be true with respect to the incorporated treaty in its domestic legal form (Dugard 472). Similar considerations apply to India (Kanwar 241).

19.  In Germany, no direct equivalent to a doctrine of ‘deference to the executive’ can be identified, although traces of ‘deference’ are noticeable in the case law of the Federal Constitutional Court of Germany (Bundesverfassungsgericht), and even more so in the jurisprudence of lower courts. France was traditionally a jurisdiction in which ‘deference’ played a large role, in particular with respect to statements by the Foreign Ministry on the content of the international legal obligations of the French Republic. This tendency to rely on executive positions has receded in recent years, partly under the influence of the European Convention for the Protection of Human Rights and Fundamental Freedoms (1950) (COE ‘Convention for the Protection of Human Rights and Fundamental Freedoms’ (signed 4 November 1950, entered into force 3 September 1953) 213 UNTS 221) (ECHR) (Arato 207). A similar development can be observed in jurisdictions under the influence of the Inter-American Court of Human Rights (IACtHR). In Mexico, for instance, the Supreme Court of Mexico (Suprema Corte de Justicia de la Nación) abandoned its traditional stance of deference to the executive in the application of international agreements after the transition to democracy in the early 2000s, and also began to assert itself as a more independent actor in questions pertaining to international law and the conduct of foreign affairs (Aust, Rodiles and Staubach 93; Rodiles 168–171).

20.  At the same time, there remain jurisdictions in which the doctrinal figure of deference to the executive does not seem to be challenged in a serious way. This applies, for instance, to Japan, where courts have developed a culture of restraint with respect to the interpretation of international agreements and the conduct of foreign affairs more generally (Takashiba 224–226). Mixed models are also conceivable. In China, for instance, the Supreme People’s Court and governmental departments jointly circulate directives for lower courts on how to apply and interpret international agreements (Xue and Jin 315). In addition, lower courts may request governmental departments to clarify the meaning of a provision in an international agreement, a procedure which is also channelled through the Supreme People’s Court (Xue and Jin 317).

21.  Separation of powers is usually discussed with respect to the horizontal distribution of powers among the three branches of government. Yet, it can also have a vertical dimension, in the sense that state powers are distributed between different levels of government. This can relate to federal systems (federalism; distribution of powers in federal systems; powers of foreign policy and national defence in federal systems), but in non-federal states there also is usually a lower level of government—called local government, municipal government, etc. To a growing extent, there is awareness that also these actors have a role to play with respect to the conduct of foreign affairs (Glennon and Sloane 35). At first sight, this development is counter-intuitive. As much as the executive was traditionally the prime bearer of the foreign affairs power, it was assumed that component states—or cities and towns—and their representatives had no role to play in the conduct of foreign affairs (United States v Belmont (1937) 331 (US): with respect to foreign relations, states ‘do not exist’; Zschernig v Miller (1968) (US)). Yet, this is more of an assumption that continues to dominate thinking in this field than is clearly spelled out in different constitutional regimes. Federal systems regulate the competence of their federal states in different ways (exclusive and shared competences in federal systems; enumerated powers in federal systems). The US Constitution, for instance, excludes the possibilities of states to enter into treaties (Art. II, s 2). Yet, this formulation has only given rise to debate about the precise contours of this prohibition. Just as there is wide variation in the different types of agreements that the federal level can enter intoand thereby manage the extent to which Congress is involved in the ‘treaty-making process’it has been argued that states may also enter into agreements which do not fall under the US constitutional law category of ‘treaties’. Recent literature from the US (Glennon and Sloane 368) has therefore challenged the view that the US is a ‘closed’ federal state (Henkin 3: US ‘virtually a unitary state’) as opposed to the ‘open federal states’ which can be found in Europe (such as Germany and Switzerland, see Fassbender 70–80). The precise contours of the competence of federal sub-units to engage in foreign affairs may also depend on the adoption of legislative acts with a pre-emptive force (see Crosby v National Foreign Trade Council (2000) (US)).

22.  A particular form of this ‘federal challenge’ to the conduct of foreign affairs is the development of a unique form of foreign relations power of the EU. Although not a federal state in the traditional sense, its organization vis-à-vis its Member States can be understood in terms of federalism (Schütze chapters 1 and 6). The projection outwards of the EU’s powers and identity has led to a new form of the combination of foreign affairs powers (Nolte and Aust 433–434). This is most noticeable in the form of so-called ‘mixed agreements’ which are concluded between, on the one hand, the EU and its Member States and, on the other hand, a third party (Eeckhout chapter 7). This practice is owed to the distribution of competences between the EU and its Member States. If Member States have transferred powers to the EU in a certain policy area, they are no longer in a position to enter into international agreements in this field. For the EU, on the other hand, it may not be possible to enter into international agreements with a wide-ranging ambit as it may lack certain powers still residing with the Member States. Hence, a requirement for a mixed agreement arises. Those kind of agreements pose their own problems in terms of the division of responsibilities between the EU and its Member States (Weiler 168). In this sense, the foreign relations law of the EU differs considerably from other federal systems such as the US and Germany, where debates about the federal treaty power and the competences of the component units have usually led to compromises according to which the federal level may enter into international agreements regardless of the internal division of competences (Missouri v Holland (1920) (US); Bond v United States (2014) (US)) or has to consult with its component units on the basis of a political compromise (the so-called ‘Lindauer Abkommen’ in Germany; Schorkopf § 4, paras 57–61). Also in India the central government can enter into international agreements irrespective of the division of competences between the different federal levels (Rajamani 155).

23.  It is not only federal entities which challenge the widely held view that the conduct of foreign affairs is a matter purely for the central government of a given state. Cities and local governments also assert themselves more broadly as internationally relevant actors (Aust chapter 2). Here, too, the conditions under which local governments can engage in international contacts and transactions vary widely, depending on the conditions of the respective domestic legal system. In some jurisdictions, the role of local governments to deal with issues of local concern is constitutionally protected. In these cases (such as for instance Germany and South Africa), there is a trend towards regarding certain international and transboundary issues as being also of local concern. Particularly noteworthy policy fields in which this development takes place concern climate change governance and the local enforcement of human rights norms (Aust chapters 7 and 9). This process is not limited, however, to jurisdictions in which local governments enjoy a robust constitutional protection. In the US, for instance, a lot of cooperation between cities and other actors outside of the US takes place on a pragmatic basis. Cooperation is informal in nature, falling into the field of what can be labelled ‘global governance processes’. Thereby, formal legal constraints are avoided and the domain of foreign relations takes on a considerably different character. Foreign affairs are no longer exclusively the prerogative of the executive of states (if that ever was the case) (Slaughter 12). Instead, foreign relations law has turned into a playing field in which different actors of different levels of government interact. In this context, states and their central governments continue to be the central actors; but increasingly they have to share the stage of foreign relations with other actors who formulate competing claims of authority.

24.  A constant trope of foreign relations law concerns the limits that might flow from foreign policy-related considerations for the protection of individual rights. Such limits might arise from different considerations. The most prominent set of cases across a wide range of jurisdictions concerns the extraterritorial applicability of individual rights (extraterritoriality). This issue is, today, no longer just a question of domestic constitutional law but has a separate, yet in some ways parallel, existence in the field of international human rights law. Article 2, paragraph 1 of the International Covenant on Civil and Political Rights (1966) (adopted 16 December 1966, entered into force 23 March 1976) 999 UNTS 171) (ICCPR or ‘Convention’), for instance, sets forth that ‘[e]ach State Party to the present Convention undertakes to respect and to ensure to all individuals within its territory and subject to its jurisdiction the rights recognized in the present Convention’. Article 1 of the ECHR stipulates that the rights and freedoms of the Convention shall be secured to everyone within the jurisdiction of the High Contracting Parties. Whereas the International Court of Justice (ICJ) (Israeli Wall Advisory Opinion (Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory) [2004] ICJ Rep 136, para. 109) and the UN Human Rights Committee (General Comment No. 31 ‘Nature of the Legal Obligation on State Parties to the Covenant’ (26 May 2004) UN Doc CCPR/C/21/Rev.1/Add.13 paras 10–11) adopt a broad view on the extraterritorial applicability of the ICCPR, the European Court of Human Rights (ECtHR) is more restrictive in its approach and departs from the assumption that the extraterritorial application of human rights is an exception. It has systematized its case law in recent years, and affirms the extraterritorial applicability primarily in two situations, ‘state agent authority and control’ and ‘effective control over an area’ (Al-Skeini and others v United Kingdom (2011) 130–137 (ECtHR)).

25.  In constitutional law, this debate has a long pedigree, dating back at least to the late nineteenth century when the US Supreme Court had to decide on the applicability of the US Constitution and its amendments to the exercise of criminal jurisdiction by a US consul in Japan, whose authority to that extent rested on an 1857 treaty between the US and Japan (Raustiala 59–68). In an early case, the Supreme Court categorically formulated that ‘[t]he Constitution can have no operation in another country’, thereby rejecting any claim by Rosswho happened to be a British citizen, but had stabbed a fellow sailor on-board a US ship in a Japanese harbourthat he should be able to avail himself of the protections of the US constitution (In re Ross (1890) 464 (US)). This view was later challenged, if only on the persuasive basis that the exercise of jurisdiction by a US consul must also rest on the US constitution. Accordingly, a much more differentiated case law has developed over time, right up until the cases in which the applicability of individual rights and guarantees for inmates at the Guantanamo military base were decided by the Supreme Court (Rasul v Bush (2004) (US); Boumediene v Bush (US) (2008) (US)).

26.  The debate about the extraterritorial reach of individual rights plays out differently across the various legal systems. In Commonwealth jurisdictions, two layers of protection need to be distinguished: on the one hand, the traditional writ of habeas corpus, the applicability of which is now generally held to also afford protection against detention abroad if the sovereign in question exercises control in fact over a given person (McLachlan (2014) 8.25); on the other hand, there is an additional layer of human rights protection in a number of Commonwealth jurisdictions, which is owed to the incorporation of international guarantees into domestic law. Here, pertinent instruments include the Canadian Charter of Rights and Freedoms of 1982, and the UK Human Rights Act of 1998, the latter giving effect to the ECHR. In both jurisdictions, courts have struggled to define the extraterritorial applicability of these domestic instruments. In recent years there seems to be a converging trend towards a factual determination of control over either a person or an areaand thus also convergence with the developments at the level of the ECHR.

27.  The picture is again different in jurisdictions with an independent catalogue of individual or fundamental rights, such as in Germany. Here, Article 1, paragraph 3 of the Basic Law sets forth, in general, that all state powers are bound by the fundamental rights set forth in Articles 1–19. On the face of it, the Basic Law does not distinguish between ‘internal’ and ‘external’ situations. Yet, the Federal Constitutional Court has recognized, in a number of decisions, that it may not be possible to guarantee the same standards of fundamental rights protection in situations with external elements (Zweitregister (1995) 41–42 (Ger)). This operation does not, then, lead to a general conclusion that fundamental rights do or do not apply extraterritorially; rather, the standards for balancing in the context of the proportionality test will vary depending on the circumstances in which fundamental rights protection is sought.

28.  Jurisdictional rules may limit the reach of fundamental rights even without short-circuiting the concept of ‘jurisdiction’ in the sense of human rights law with the distinct notion under public international law (Milanovic 19–40). In a recent case on the transboundary transfer of data in the context of security cooperation, the German Federal Constitutional Court remarked that the reach of the fundamental rights of the Basic Law is necessarily limited due to respect for different legal orders (BKA-Gesetz (2016) 325 (Ger)). This finding has also to do with the basic premise of constitutional law, that it can only bind the state which is governed by the respective constitution. This axiomatic principle is coming under considerable strain, since cooperation may create deficits in terms of the protection of individual rights. In recent years, this has become most notable with respect to the limitation of fundamental rights in the context of the fight against terrorism. In particular, domestic (and international) courts have had to grapple with the implementation of UN Security Council resolutions (Ahmed v HM Treasury (2010) (UK); Abdelrazik v Canada (2010) (Can)). Other high profile cases have involved implications of third states in the program of so-called ‘extraordinary renditions’ (Khadr v Canada (Prime Minister) (2010) (Can)).

29.  A more recent challenge for foreign relations law relates to the implications of foreign affairs for democracy and the rule of law. The relationship between the conduct of foreign affairs and these central notions of modern constitutionalism has become more integrated in recent years. This is owed to the growing visibility of international law—and, for some states, EU law—in the domestic context. With this growing visibility, the ambit and scope of foreign relations law changes. It is no longerif it ever wasexclusively about the external projection of state power and related internal discussions about the allocation of state powers. With ‘the outside’ increasingly impacting on ‘the inside’, those on the inside wish to make themselves heard and ensure that ‘foreign entanglements’ are not working to the detriment of established constitutional guarantees.

30.  In some EU jurisdictions, this developing debate can take inspiration from the parallel discussion about constitutional limits to EU integration. In this context, it has been the German Federal Constitutional Court (Federal Constitutional Court of Germany (Bundesverfassungsgericht)) in particular which has developed an elaborate line of case law highlighting that European integration must not curtail essential principles of the German constitutional order. Its early case law focused on the protection of individual rights against measures of the European Communities. Later casesbeginning with Maastricht (1993) (Ger) and culminating with the 2009 decision on the Treaty of Lisbon (Lissaboner Vertrag Case (Ger))focused more on the principle of democracy. This principle is set forth by Article 20 of the Basic Law and protected by the Constitution’s so-called ‘eternity clause’ in Article 79, paragraph 3 (entrenched clauses). The case law of the Constitutional Court is, to a large extent, premised on the assumption that there is a considerable deficit of democratic legitimacy at the European level (see Germany’s Federal Constitutional Court Act: March 12, 1951 (as Amended to July 12, 2012)). Accordingly, this deficit needs to be compensated by domestic actors, in particular the national executives who occupy a central role in EU law-making processes due to the composition of the Council of the EU. Beyond the doctrinal debate, this development has a larger significance insofar as it relates to the construction of collective identities. The case law of the German Constitutional Court revolves around the ‘constitutional identity’ of the Federal Republica relatively novel concept in German constitutional law and, at the same time, a complimentary notion to the ‘national identity’ mentioned in Article 4, paragraph 2 of the TEU (Wendel 572). Questions pertaining to foreign affairs power thus turn into a battle ground for the formulation of particular collective identities vis-à-vis a perceived other which is ‘foreign’ in nature.

31.  This defensive line of argumentation has now spilled over into the debate about the impact of international law on domestic constitutional systems. It has also been well received in a number of non-liberal systems which took inspiration from this line of critique. Actors in the Russian constitutional system, for instance, have followed pronouncements of the German Federal Constitutional Court that the constitutional identity of the Federal Republic needs to be preserved against international and European influences (Görgülü (2004) 319 (Ger)). Recent Russian legislation (Amendment to the Law on the Constitutional Court, entered into force on 14 December 2015 (Russ)), based on previous case law of the Court (Judgment No. 21/II/2015 (2015) (Russ)), introduced a procedure by which the compliance of judgments of the European Court of Human Rights with core components of the Russian Constitution can be scrutinized (see further Hartwig 1–22). Criticizing this move certainly bears the risk of formulating double standards. In any case, it highlights the dangers of introverted positions being formulated by liberal states and their courts which unwittingly may turn into blueprints for other systems.

32.  In conceptual terms, this growing awareness of the democracy-related and rule of law-related implications of foreign affairs can be seen to further challenge traditional notions of dualism which strictly separate between the international and domestic levels of law. If a strict dualism could be policed by constitutional systems, the dangers for domestic democracy could only be minimal. Yet, the general public increasingly perceives international cooperation as potentially worrisome, at times based on misleading facts and information. The rhetoric accompanying the announcement of the withdrawal of the US from the Paris Agreement on Climate Change ((12 December 2015, entered into force on 4 November 2016) UN Doc FCCC/CP/2015/10/Add.1 Annex) is a case in point.

33.  In this context, it should be considered whether this trend is also an expression of changing power dynamics on the international level. Foreign relations law has so far been a field of legal research which was dominated by fairly strong states from the ‘Global North’ such as the US, the UK, and, to a lesser extent, Germany. Traditionally, the foreign policy of these strong states was an external projection of state power, even if undertaken in some cases in the name of liberal values pertaining to democracy, the rule of law, and human rights. In addition, the shaping of the international economic order was undertaken primarily in order to ensure export opportunities for domestic industries. If foreign relations law is about the translation of international commitments into the domestic legal order and the question of the partition of competences between state organs in this field, the development of this field is, arguably, to some extent contingent upon the development of its international counterpart. Today, there is a growing awareness that international rules and principles developed in this context also ‘hit home’ and limit the policy space of these traditionally strong, norm-exporting countries. It has been rightly criticized that it amounts to a certain degree of hypocrisy if the limits of international cooperation are now stressed in the name of Western values of democracy and the rule of law (Stoll and Holterhus 341).

34.  The field of foreign affairs and foreign relations law is affected by global trends pertaining to the changing fortunes of the nation state and globalization. A couple of years ago, an optimistic spirit prevailed that international law would develop towards a more integrated system, possibly even operating in a constitutionalist mode. Since international law and foreign relations law are distinct yet related subject matters, changes in the international legal system also impact on the foreign relations law of states, if only indirectly. Accordingly, it can be wondered how foreign relations law will be affected by the more critical attitude that is now prevailing towards international law in many circles (Krieger and Nolte). In any case, it is unlikely that we will soon face an end to the period of the nation state. At the least, the nation state will most likely not be replaced with superseding global structures. At the same time, globalization has not gone away. There still exists a dense network of obligations for states. The global economy is highly interconnected. Migration flows are a challenge, both for states whose citizens are attempting to escape to other regions of the world, and for states which need to accommodate migrants and refugees (immigration). All this goes to show that foreign relations law will continue to occupy a central role in the constitutional system of many states, since these globalizing influences need to be mediated, channelled, and translated into domestic legal procedures.

35.  At the same time, foreign affairs as a field for constitutional law has considerably diversified. It has for quite some time been characterized by a standard set of debates which continue to remain central to the debateseparation of powers and the enforcement of the rights of individuals in foreign policy-related issues being the most salient topics. Yet, these debates are now set in a wider context which has also come to be defined by the growing informality of global governance processes. Of these, the ‘traditional’ conduct of foreign affairs is an important partbut not the only one. States and their national executives remain central actors, but they find themselves acting in cooperation and at times in conflict with a plethora of other actorsincluding international organizations, non-governmental organizations, and transnational businessesas well as with the sub-divisions of states themselves (federal states, cities, and local governments). The tensions which can arise from this more variegated playground of foreign affairs need to be mitigated by the domestic law of states. Accordingly, foreign relations law has taken on a new importance. What is more, due to the greater variety of actors, the field is also expanding into areas which were previously considered to be unrelated to the conduct of foreign affairs. It remains a challenge in many jurisdictions to think through the conceptual implications caused by this development.