In a statement of 18 January 1985 concerning withdrawal from the Nicaragua case,Footnote ¹ the US government addressed the implications of the case on the Court itself in the following terms:

This paper will examine whether (or to what extent) the predicted trends came to pass and what their consequences have been for the role of the Court within the overall system for settlement of disputes.Footnote ³

In brief, I will present mixed evidence, some pointing in the direction that the US government had feared, but overall tending to show that the predictions of harm to the Court as an institution were exaggerated. Having not been involved in the case myself, I will try to give a balanced picture by filling in a few data points on what has and has not happened in the 25 years since Nicaragua.

When the Nicaragua case was pending, I was at the very outset of my career as a legal academic, having served prior to that time in the Office of the Legal Adviser in the US Department of State and having participated in that capacity as part of the US legal team for the Tehran Hostages caseFootnote ⁴ and the advisory opinion on Interpretation of the Headquarters Agreement between the WHO and Egypt.Footnote ⁵ Those experiences inclined me towards strong support for the International Court of Justice as a valuable organ for peaceful settlement of disputes.

In 1985, after the jurisdictional decision in Nicaragua but before the final merits judgment, I was enlisted during my first year as a professor at Columbia Law School by former US State Department Legal Adviser John R. Stevenson to organize a study panel for the American Society of International Law on International Adjudication and the Jurisdiction of the International Court of Justice. The motivation for convening that study panel was to address the whole range of concerns about the Court that the US government under Legal Advisers Davis Robinson and Abraham Sofaer had articulated in explaining the US decisions to refuse to participate in the merits phase of the case and later to terminate the US acceptance of compulsory jurisdiction.Footnote ⁶ The study panel commissioned a series of papers to shed light on the policy decisions that the United States and other states would be taking in the aftermath of Nicaragua. We completed our study soon after the merits judgment was handed down in 1986, and it was published as The International Court of Justice at a Crossroads in 1987.Footnote ⁷ It may be timely to revisit some of the questions examined in that study now that 25 years have elapsed.

The data and analysis contained in our Crossroads study 25 years ago can provide a baseline for assessing the nature, direction, and extent of trends affecting the Court itself and its role in peaceful settlement of international disputes. Beginning from those baselines, let me address the following questions:

1. 1. What trends do we discern in states’ acceptance of compulsory jurisdiction under the optional clause of Article 36(2) of the ICJ Statute and comparable trends for compromissory clauses under Article 36(1)?

2. 2. What trends do we discern in the pattern of cases that states are choosing to bring to the Court?

3. 3. With respect to subsequent cases – notably those sharing features with Nicaragua, especially cases challenging military or paramilitary activities – do we discern the Court itself having made any adjustments in its practice or doctrine that might be considered responsive to criticisms of the Court's handling of the Nicaragua case? If so, are those adjustments salutary from the point of view of the Court's role in international dispute settlement?

4. 4. What has been the impact of Nicaragua on compliance with subsequent rulings? Has the reception of the Court's decisions been compatible with a perception of the Court as a juridical rather than political (politicized) body in fulfilment of the expectations of participation in a system of legal dispute settlement? Are the addressees of contentious judgments and advisory opinions treating both categories of decision as having been grounded in a legally well-justified conception of the Court's role in the resolution of legal disputes, regardless of the political or politicized context in which they arise? In particular, are state litigants complying with decisions in cases to which they are parties, as they are obliged to do under Article 94 of the UN Charter?

1. Trends concerning acceptance of compulsory jurisdiction under Article 36(2)

First, let me mention some of the trends of the last 25 years concerning acceptance of the Court's jurisdiction under the optional clause of Article 36(2) of the ICJ Statute. Contrary to the predictions of some at the time of the Nicaragua case, there has not been a stampede for the exits with respect to compulsory jurisdiction. As documented by Leo Gross in the Crossroads study, the fraction of states nominally accepting Article 36(2) jurisdiction as of the mid-1980s represented approximately one-third of the eligible ‘international judicial community’ at the time.Footnote ⁸ That proportion has not only held steady, but has actually inched up a little bit, from 47/161 (28–29 per cent) in the mid-1980s to 66/192 (over 34 per cent) today.Footnote ⁹ Although all but a handful of these acceptances do come with reservations, there has not been a general retreat from compulsory jurisdiction, but rather a modest increase.

With that general proposition in mind, let us now examine some of the particular features of changes in acceptances of Article 36(2) jurisdiction over the last 25 years. First of all, there are four states that did accept compulsory jurisdiction at the time of the Nicaragua case but no longer do so. The United States gave the required six months’ notice of termination in October 1985 and has not been subject to that form of jurisdiction since April 1986.Footnote ¹⁰ Israel gave similar notice on 21 November 1985.Footnote ¹¹ El Salvador, which had renewed its acceptance for a ten-year term from 26 November 1978, did not register renewal following the expiration of that term in November 1988, and its declaration was removed from those published in the Court's Yearbook not long thereafter.Footnote ¹² Those three terminations are presumably direct consequences of the Nicaragua case. The fourth, by Colombia in December 2001, was in anticipation of the imminent filing by Nicaragua of a case against Colombia over a territorial and maritime boundary dispute.Footnote ¹³

Next, several of the states that did accept compulsory jurisdiction in 1984 subsequently revised their declarations to add reservations that would appear to shield them from Nicaragua-type suits. According to Leo Gross's study in Crossroads, as of 1984 only eight states made exceptions for cases involving armed conflicts or use of force.Footnote ¹⁴ Two of those were El Salvador and Israel, whose declarations are no longer in force; the six others at that time were India, Kenya, Malawi, Malta, Mauritius, and Sudan.Footnote ¹⁵ Of the states that accepted compulsory jurisdiction without such a reservation in 1984, several have amended their declarations to exclude such disputes. Honduras did so as of 6 June 1986,Footnote ¹⁶ which we may assume was directly responsive to the pendency of the Nicaragua case and the possibility (which materialized the next month) that Nicaragua would initiate legal action against its neighbours on whose behalf the United States had claimed to be acting in collective self-defence.Footnote ¹⁷ Thereafter, a few other states likewise amended their existing declarations to add such a reservation or included one when filing a new declaration. For example, Nigeria amended its 1965 declaration, which had not had an armed force reservation, to add an exclusion for ‘disputes relating to or connected with facts or situations of hostilities or armed conflict, whether internal or international in character’.Footnote ¹⁸ Of the states that accepted compulsory jurisdiction only after Nicaragua, Djibouti, Germany, Greece, and Hungary have done so subject to exceptions for military action.Footnote ¹⁹ Based on a comparison between the historical data as of 1984 and the current situation, it would appear that the number of states accepting compulsory jurisdiction subject to a military-activities exclusion has inched up slightly in absolute terms – from eight to 12 – while, in relative terms, the proportion of states accepting compulsory jurisdiction subject to such an exclusion has remained rather steady – 12/66 (18 per cent) today, as compared with 8/47 (17 per cent) in 1984.

Before leaving the question of patterns of jurisdictional acceptance, it is worth comparing the trends under Article 36(2) to the corresponding question of whether states have continued to display confidence in the Court by adding to the set of treaties with compromissory clauses, under which the Court's jurisdiction over a dispute concerning the treaty could be invoked unilaterally by an applicant under Article 36(1) of the Court's statute, without the necessity of specific consent after the dispute arises. In this regard, we may observe that states have continued to make provision for resort to the Court in dispute-settlement clauses in bilateral and multilateral treaties, but the rate of doing so may be lower than in prior periods and may be qualified by more exceptions. According to information on the Court's website, at least 35 such treaties have entered into force subsequently to the Nicaragua case,Footnote ²⁰ which would be more than one per year, but only a small fraction of all treaties and a considerably lower rate than prevailed in earlier decades.Footnote ²¹ In general, treaties with jurisdictional clauses drafted in the post-Nicaragua period have been framed to allow states to withhold consent from ICJ dispute settlement, while earlier treaties did not always have such an explicit opt-out feature. Although a detailed study of patterns of treaty-based acceptance before and after Nicaragua remains to be carried out, it is likely that the decision affected the willingness of states to enter into treaties with jurisdictional clauses, thereby leaving lasting effects on the network of jurisdictional relationships created by such treaties.

As would be expected, the United States has consistently refused to grant consent to ICJ jurisdiction whenever it has become party to treaties subsequent to the Nicaragua case, or it has entered a reservation to the dispute-settlement article where the clause in question does not explicitly provide for an opt-in/opt-out mechanism. Thus, for example, the United States reserved against the compromissory clause of Article IX of the Genocide Convention upon depositing its instrument of ratification in 1988 and against Article 22 of the Convention on the Elimination of Racial Discrimination in 1994, in both instances stating that the specific consent of the United States would be required in each case as a condition of ICJ jurisdiction. It also invoked the opt-out clause of Article 30(2) of the Convention against Torture upon becoming party to that treaty in 1994. To the extent that Nicaragua motivated the United States and other states to curtail their jurisdictional exposure under compromissory clauses, the impact of the decision would be felt outside the ambit of the Article 36(2) compulsory jurisdiction system.

2. Trends concerning cases brought to the Court

The increase in the Court's caseload since Nicaragua has been remarkable. In contrast to the early 1980s, when the Court in a typical year would have two or three cases on its docket, in recent years it has been juggling a dozen or more at any given time. A significant number of these cases have come from Central America, with the participation of Nicaragua's neighbours that might have been inclined to curtail their involvement with the Court as the United States did.Footnote ²² Still, it is an incomplete response to point to the fact that the Court has been very busy in recent years. We would also want to know whether the mix of cases has changed since Nicaragua, as regards the kinds of case that are being brought and the states that are involved as applicant, respondent, or prospective intervener, and whether the cases that reach the Court lead to useful results in terms of achieving an enduring settlement of the underlying dispute. These questions relate to those concerning compliance, to be considered further below.Footnote ²³

Most commentators assume that Nicaragua represented a turning point for the mix of cases being brought to the Court, in terms of the kinds of state choosing to bring their disputes there. There has indeed been a perceptible shift in the docket from the Court's first 20 years, when its main clients were developed Western states, through a period of gradual change in its second 20 years, and then a pivotal point with Nicaragua, when its traditional clientele from Western Europe and North America retrenched (at least for some years) from affirmatively invoking the Court's jurisdiction. After Nicaragua, a number of Western states – including the United States – have continued to find themselves as respondents before the Court, despite their unwillingness to be sued there on the disputes in question. The big growth area in the post-Nicaragua period has been with the developing and non-Western countries, which now account for a large proportion of the Court's cases, both by bringing suits against Western states and by submitting their own disputes with other developing countries by special agreement or otherwise.

Several scholars have published analyses of what they call the ‘decline of the ICJ’ and have tried to explain their perception that the Court's relative stature has diminished, in that its docket has not increased commensurately with the growth in the number of states or in inter-state disputes in the period under study,Footnote ²⁴ and that the most powerful states (the ‘top-ten economies’) have largely refrained from bringing their disputes to the ICJ in the last few decades.Footnote ²⁵ This literature generally views Nicaragua as a turning point, assertedly because Western democratic states thereafter ceased to view the Court as an impartial forum for resolving their disputes.Footnote ²⁶ Scholars writing in this vein proffer empirical analysis of the Court's caseload, along with the application of quantitative methods to test certain hypotheses, such as whether states that score higher on measurements of democracy have been less likely in the more recent period to bring their disputes to the Court.Footnote ²⁷ The authors of these studies have not, in my view, proved either that the ICJ is in absolute or relative decline or that any of the several proffered hypotheses can completely account for the perceived shift in the mix of litigants. (One might as well assert that the US Supreme Court is in decline because it puts out fewer decisions relative to the increasing population of the United States.) I mention these studies here because their proliferation in the last ten years has bolstered the perception in certain circles (especially in the United States) that the Court has become a forum in which the weak sue the strong, or the weak sue each other, but no longer one in which major states feel comfortable bringing disputes as significant as those they chose to submit in earlier years. This literature peaked about five years ago and does not yet take account of recent developments, such as Germany's suit against Italy over jurisdictional immunity in litigation related to German conduct during the Second World WarFootnote ²⁸ or Australia's suit against Japan over whaling.Footnote ²⁹

A salient feature of the Court's docket in the last quarter-century has been the invocation of the judicial process in the midst of armed conflict, or to obtain a judicial ruling on the lawfulness of a forcible action taken in the recent past, or to attempt to head off anticipated coercive action, or to challenge the legality of the choices states have made to deter or defend themselves against armed attacks. Nicaragua was, of course, not the first such case: writing in the Crossroads study, Oscar Schachter identified 12 previous ICJ cases involving use of force, including nine aerial incident cases, Corfu Channel, Fisheries Jurisdiction, and Tehran Hostages.Footnote ³⁰ It appears that Nicaragua gave a considerable boost to such cases.

Concerning cases of the Nicaragua type, Jonathan Charney wrote in Crossroads:

After speculating that the Court may have made a calculated choice to attract states from the developing or non-Western world, at the expense of its traditional supporters in the developed West, Charney concluded that:

Evidently, the ‘interested parties’ that Charney had in mind did not see fit to follow this advice. Rather, they have brought quite a few cases pressing further along the Nicaragua lines. Examples include (non-exclusively), from the contentious docket:

• • Libya's cases brought against the United States and United Kingdom over the Lockerbie incident (1992);Footnote ³³

• • Iran's Aerial Incident and Oil Platforms cases brought against the United States (1989, 1992);Footnote ³⁴

• • Bosnia's case against Serbia under the Genocide Convention (1993);Footnote ³⁵

• • Croatia's case against Serbia under the Genocide Convention (1999);Footnote ³⁶

• • Serbia's cases against ten NATO states over their intervention in Kosovo (1999);Footnote ³⁷

• • Armed Activities cases brought by the Democratic Republic of the Congo against Uganda, Burundi, and Rwanda (1999, 2002);Footnote ³⁸

• • Georgia's case against Russia under the Convention on the Elimination of Racial Discrimination, brought while the two countries were fighting (2008);Footnote ³⁹

and from the advisory docket:

• • the Nuclear Weapons advisory opinion requests from the General Assembly and World Health Organization;Footnote ⁴⁰

• • the General Assembly's request on the Wall in the Occupied Palestinian Territory.Footnote ⁴¹

In view of the illuminating discussion of use-of-force cases elsewhere in this symposium, I do not venture an assessment of these actions here, other than to observe that I share doubts as to whether litigation of this type has contributed to stable resolution of the underlying situations.

3. Adjustments by the Court in its post-Nicaragua jurisprudence

How has the Court itself responded to the criticisms made of its performance in the Nicaragua case? What adjustments, if any, has it made in aspects of its practice or doctrine relevant to its institutional role, in the sense of structural aspects having to do with how the Court and its potential litigation customers engage with each other?

On the core question of the Court's attitude towards legal disputes in their political context, subsequent cases consistently affirm that the Court will not decline to decide legal questions falling within its jurisdiction because of their interaction with political factors. That message is prominent on the surface of innumerable cases in a continuous line that pre-dates Nicaragua, of which the Kosovo Advisory Opinion would be illustrative.Footnote ⁴²

Probing beneath the surface, however, one wonders whether the Court's proclaimed insistence that it must decide legal questions within its jurisdiction regardless of political implications is perhaps sometimes coupled with a more cautious approach to jurisdiction proper than it adopted in Nicaragua. For example, in dismissing Georgia's case against Russia under the Convention on the Elimination of Racial Discrimination, the Court appears to have taken an unprecedented narrow view of how to interpret a compromissory clause with a standard formulation on disputes that cannot be resolved through negotiations.Footnote ⁴³ There may be reason to believe that the Court has occasionally retrenched from what would otherwise be a well-founded jurisdictional basis, in order to avoid rendering decision in a case with high political salience. Several participants in the symposium who mentioned the Georgia–Russia case were constrained by virtue of their role as counsel therein from criticizing the Court's disposition of it. As I am not under the same inhibition, I can express my perplexity as an outside observer that the same Court that found jurisdiction in Nicaragua, under a bilateral treaty that Nicaragua had never raised in diplomatic negotiations with the United States, could have set the bar so much higher for Georgia. By contrast, in the Oil Platforms case, the Court reached out (or overreached) to make evaluations under the Charter-based use of force, which were unnecessary for disposition of the case and arguably beyond the scope of the jurisdictional clause in the treaty involved.

Perhaps also the Court in certain cases has slowed the pace of proceedings after taking a decision one way or the other on provisional measures requested in time of armed conflict, in a display of prudence to avoid rendering judgment in circumstances under which its ruling might be ineffectual. Would such an explanation help to make sense of the 14-year span between application and final judgment in the Bosnian Genocide case, for example? And perhaps the ‘Solomonic’ nature of its judgment there, and also in the Oil Platforms case, in which neither side actually won what it asked for but also neither side totally lost, is another technique by which the Court has avoided entering a final judgment that is likely to be disobeyed.

Another sort of corrective action involves the stringent critiques of the Court for having fallen short of procedural fairness in the Nicaragua case, especially as regards its denial without a hearing of the application of El Salvador to intervene in the proceedings.Footnote ⁴⁴ Other complaints about procedural fairness to litigants have been made subsequently to Nicaragua, such as by the United States in respect of the order of provisional measures on an ex parte basis in the admittedly urgent LaGrand matter.Footnote ⁴⁵ Procedural shortfalls have complicated the task of the Court's supporters in the United States, who have tried to persuade relevant political and judicial actors in the United States to comply with the Court's rulings against the deeply entrenched perception that the Court did not act fairly towards the United States and its allies in Nicaragua.

4. Impact on compliance in other cases

Finally, I turn to the impact of the Nicaragua case on compliance with the Court's judgments in other cases. The fact that the Court entered provisional measures and final judgment on the merits in Nicaragua, in circumstances in which it was virtually certain that the United States would not comply, could have led to a cascade of noncompliance by other parties with decisions addressed to them. In the worst-case scenario, not only the United States, but also other litigants would perceive the Court's rulings as having been rendered for political rather than legal reasons and would therefore no longer treat them as entitled to the respect due to decisions of a juridical organ.

Fortunately, that worst-case scenario did not transpire. I had occasion to investigate patterns of compliance in connection with efforts in the United States to persuade several state and federal courts, and ultimately the US Supreme Court, that the Court's judgment in the Avena case should be implemented within the US legal system.Footnote ⁴⁶ We now have the benefit of a considerable body of empirical work that endeavours to analyse compliance with the Court's decisions over time, to compare compliance records under the different modes of ICJ jurisdiction, and to compare the ICJ's record with that of other tribunals.Footnote ⁴⁷ On the basis of such analysis, one can be reasonably confident that the addressees of ICJ rulings generally try hard to achieve compliance and usually succeed without too much delay, resulting in compliance rates of at least two-thirds of all judgments and orders and up to 80 per cent of final judgments over time.Footnote ⁴⁸ That good news has to be qualified, however, with reference to related data finding differential rates of compliance, depending on whether the basis for jurisdiction was a special agreement (85.7 per cent), a compromissory clause (60 per cent), or compulsory jurisdiction under Article 36(2) of the Court's statute (perhaps as low as 40 per cent according to one study that would benefit from updating).Footnote ⁴⁹

The impact of the Nicaragua judgment on compliance by the United States with subsequent rulings addressed to it was unfortunately not favourable. The attempts to enforce the Nicaragua judgment in US courts – whatever may have been their motivations or wisdom at the time – ultimately had a deforming effect on subsequent efforts to enforce the Court's decisions in the series of cases involving the Vienna Convention on Consular Relations.Footnote ⁵⁰ In the Vienna Convention cases, the lower courts and ultimately the US Supreme Court took note that the sole prior instance in which domestic judicial enforcement of an ICJ judgment had been sought had resulted in a holding that such judgments were not enforceable in US courts at the instance of private persons.Footnote ⁵¹ The courts disregarded all arguments made by petitioners and their amici for distinguishing the Vienna Convention cases from the Nicaragua precedent.

In my view, the US courts correctly declined to enforce the Nicaragua judgment in a suit brought by private parties, involving military matters in which courts typically do not intervene, in which no self-executing treaty was involved, and in which both the executive and the legislative branches had repudiated the judgment. In the subsequent cases involving enforcement of the Avena judgment, each of those factors pointed in the opposite direction. Medellín v. Texas and related cases involved a treaty whose purpose is to protect private persons and is of the sort typically enforced by courts. That treaty had been approved by the US Senate and brought into force on the assumption of its self-executing character. The president had explicitly supported compliance with the Avena judgment, had called on state courts to give effect to it, and had asked the Supreme Court for a ruling to that effect. Congress had not opposed compliance. Even so, in denying Medellín's petition and allowing him to be executed contrary to the binding obligation embodied in the Avena judgment, the Supreme Court cited the court of appeals judgment in Committee of United States Citizens Living in Nicaragua v. Reagan as the only relevant prior case.Footnote ⁵² Presumably, the justices who formed the majority in Medellín, led by Chief Justice John G. Roberts, Jr, had found a lesson in Nicaragua that the United States cannot relinquish power to change rules of decision in US courts to the same body that rendered that judgment.