The Law of Succession of State Responsibility in the Crevice of History

[WANG Sijie is a LLM student at the London School of Economics specialising in public international law.]

On 28 July 2026, the International Law Commission (ILC) adopted the Report of the Working Group on ‘Succession of States in Respect of State Responsibility’, and decided to terminate the work on the topic. (A/81/10 [94]) None of the documents produced during the process – notably the Special Rapporteur’s five reports and the Draft Guidelines – therefore represents the ILC’s position on the substantive law. According to the Working Group, given the ‘problems of methodology, substance and form’, it would be ‘imprudent’ to carry the project further. (A/CN.4/L.1004/Rev.1 Annex [105]-[107])

That outcome contrasts with the optimism a decade earlier. The ILC’s earlier draft articles on the succession of treaties, State property, archives and debts, and nationality left responsibility unaddressed, (A/CN.4/L.1038 [6]) while the draft articles on State responsibility left succession outside their scope. (A/56/10 51) The post-Cold War State succession in Eastern Europe highlighted the issue, where responsibility was invoked against successor States yet no consensus emerged. (Xue [23]) Meanwhile, such practice convinced scholars that norms of State succession were evolving ‘after the new wave of the creation of new States’, a view reflected in the resolutions of the International Law Association in 2008 and Insititut de Droit International (IDI) in 2015. When the Special Rapporteur advanced his proposal in 2016, the ILC was confident that the time was ripe for codification. (A/71/10 Annex B [33])

Ten years later, the ILC concluded that it was not. This blog post agrees that the Draft Guidelines are methodologically problematic in their collection and interpretation of State practice, but argues that the project failed not for the competence but because of timing. The foundations of the ‘clean slate’ principle have collapsed yet the practice displacing that norm has not crystallised into a rule of automatic succession. The absence of a conclusion at this stage is therefore not a failure but a proper contribution by the ILC, and one whose implications reach beyond succession of State responsibility to the ILC’s current work on other aspects of international wrongdoing.

Problematic Methodologies and Disputed Compromises

Methodological difficulties have been haunting the project since its inception. The absence of a comprehensive examination of State practice, especially that of African and Asian States, led Member States to question the validity of the general rules the Special Rapporteur derived. Further doubts arose over the nature of practice collected; the Special Rapporteur relied heavily on treaties, where the consent to assume responsibility may be read either as affirming a rule of automatic succession or as contracting out of one of non-succession. (A/CN.4/L.1038 [21]-[22]) The scarcity of available practice also produced an over-reliance on academic writing, a shortcoming long criticised in the Sixth Committee. (A/CN.4/L.1004/Rev.2 [104])

These flaws left many provisions too vague to support any conclusion about the legal effects of succession. Draft Guidelines 10 to 11 are illustrative. Where a predecessor State that has committed an internationally wrongful act ceases to exist, the Draft Guidelines do not settle whether the successor State succeeds to the responsibility, providing only that the injured State and the successor State should ‘agree on how to address the injury’. (A/CN.4/L.1004/Rev.2 Annex II Draft Guidelines 10, 10bis, 11) The Special Rapporteur did account for the shift in practice in the second half of the 20^th century, when non-succession ceased to dominate these scenarios; however, practice consisting mostly of bilateral treaties cannot evidence an emerging norm of automatic succession. (A/CN.4/719 [152]-[156], [167]-[185]) Building upon largely identical practice, IDI had affirmed automatic succession under such circumstances (pp. 111-128); the Draft Guidelines, instead, adopted a ‘middle-ground approach’ attaching no substantive legal effects. (A/CN.4/751 [6]) Yet such a codification serves little purpose if only a negotiated outcome is, in most cases, attainable; States turn to the ILC precisely because ad hoc settlements are largely unsatisfactory. (p. 148) The Draft Guideline, therefore, came to a conclusion termed pactum de negotiando but effectively declared non liquet. (A/CN.4/751 [18]) 

The ‘middle-ground approach’ won neither the members of the ILC nor the Member States in the Sixth Committee. To those favouring automatic succession, the ambiguous legal effects understate the shift in State practice. To those sceptical of this development, guidelines pointing towards succession in most cases already depart from the ‘clean slate’ principle and even a softened endorsement is unacceptable. (A/CN.4/751 [11]-[15]) The Special Rapporteur and the Working Group tries to win, now to humiliate, first one position and then another, and uniformly arrays all of them against the Draft Guidelines. As the Working Group ultimately concluded, offering no output was preferrable to offering one ‘too ambiguous to be useful’. (A/CN.4/L.1004/Rev.2 [103])

A Proper Codification in the Wrong Century

Is practice here as scarce as the ILC suggests? Instances of succession involving State responsibility are hardly rare given the frequent border changes before 1945; the ‘clean slate’ principle itself was distilled from a consistent body of practice including the awards in Robert E. Brown and Hawaiian Claims, and the diplomatic settlements following the dissolution of Gran Colombia, (A/CN.4/719 [167]) the unification of Italy, French annexation of Madagascar, (Dumberry, 65-70) and the cession of Alsace-Lorraine. (A/CN.4/731 [93]) Had the Special Rapporteur not insisted on capturing the ‘new developments’ marked by the ‘humanisation’ of international law and the recognition of individual victims’ claims, (A/71/10 Annex B [34]) ample practice would have been available.

Those very ‘new developments’, however, coincided with an epoch of dramatic transformation in international law; in other words, the Draft Guidelines fall into a crevice of history. The arguments supporting non-succession date from the age of colonialism, when automatic succession would render strong powers responsible for wrongful acts committed by ‘small and backward’ nations, setting up ‘a premium on misgovernment’. (p. 178) The competing norm first emerged in decolonisation, in the post-independence arrangement of Commonwealth colonies in the 1940s and 1950s, under which the new States assumed the ‘obligations and responsibilities’ arising from international agreements applicable to them, as stipulated in the UK’s agreement with Jordan (6 UNTS 143, Art 8), Burma (70 UNTS 183, Art 2), Ceylon (86 UNTS 25, Art 6), and Malaysia. (279 UNTS 287) This pattern recurs in the settlement of the Suez Crisis, where the United Arab Republic (UAR) expressly accepted succession to the responsibility arising from Egypt’s expropriation of the Suez Canal Company, (732 UNTS 86; 343 UNTS 159) and in the lumpsum compensation agreements in 1970s, notably Egypt’s succession to responsibility for the UAR’s confiscation of US property (1070 UNTS 25, Art 1) and Vietnam’s undertaking to compensate US losses preceding the unification. (2420 UNTS 91, Art 1) A change of directions thus appears eminent.

Yet the political context of that shift explains the scarcity of practice capable of proving a change in the general rule. Agreements between newly independent States and their former suzerains settling colonial debts, property and responsibility were in most cases the product of laborious bargaining. (p. 534) The practice of colonial independence is therefore far from uniform. The arrangements between Italy and Libya (2328 UNTS 149, Art 5) and Italy and Somalia, (A/CN.4/730 [81]) for example, explicitly excluded succession to State responsibility. The context-specificness is also reflected in settlement of Suez Crisis, a pivotal case for the Special Rapporteur. (A/CN.4/719, [154]) While France acquired compensation for expropriated properties through a petition-and-registration mechanism, (732 UNTS 86, Protocol II) the UK received ex gratia payments and waived the UAR’s responsibility for the confiscation of Suez Canal Base in exchange for the UAR’s renunciation of claims for the damages caused by British forces. (343 UNTS 159, Art 4, Note 10) Under both treaties, the UAR could be said to have succeeded to the responsibility; however, the obligations transferred reflect reciprocal concessions rather than recognition of a general norm. Similarly, in the lumpsum compensation agreements in 1970s, Nasser’s expropriations went uncompensated until Sadat’s realignment of Egyptian foreign policy, and Vietnam’s succession followed the end of the Cold War; in both cases, succession was the precondition of diplomatic reconciliation, better understood as a choice made for particular ends than as evidence of opinion juris supporting the ‘existence of general rules’. (p. 182; A/CN.4/L.1038 [38]) 

No Conclusion May be the Best Conclusion

The mainstream rhetoric that justifies automatic succession by appealing to the ‘humanisation’ of international law, while condemning non-succession as inherently ‘colonial’, remains doubtful. The delicts succeeded to sometimes arise from repressive policies imposed against the local population such as the torture committed by British Kenya during the Mau-Mau uprising, ([95]) or the destruction or nationalisation of foreign assets – often those of the former suzerain – during struggles for self-determination. Requiring former colonies to answer for such harms tends to perpetuate existing unequal economic conditions and consolidates the underdevelopment. (pp. 560-61) In both circumstances, applying non-succession and holding the former colonial powers liable would be the fairer arrangement. (p. 128) The ‘clean slate’ principle is not inherently conservative, nor is automatic succession necessarily a ‘progressive’ development.

The failure to settle a guiding principle at this stage may therefore be the realistic outcome of these unsuccessful Draft Guidelines. Lauterpacht argued that the absence of consensus on certain norms creates no lacunae; an international judicial organ should decide by reference to a ‘more general principle’ entailing a ‘substantial measure of agreement’. (p. 85) That assertion, however, does not carry over to the Draft Guidelines, whose very purpose was to challenge the ‘substantial measures of agreement’; (A/CN.4/743 [9]-[10]) the PCA took the same view in the Lighthouse Arbitration, claiming that the variety of theories, the political considerations and the rarity of judicial decisions preclude any general principle governing the transfer of State responsibility upon succession. (pp. 91-92) The interim solution is therefore ‘case-by-case analysis’, where negotiated agreements and judicial settlements can recourse to no codified principles but their specific context. (A/CN.4/L.1038 [25]) The need for a general solution has not disappeared, and the ILC remains the proper organ to supply one should State practice develop further. But in this crevice of history, the ILC cannot supply what practice has not produced; had the Draft Guidelines instead imposed automatic succession over the opposition of Member States, the value of that contribution would itself be questionable.

Conclusion

Overall, the ILC’s attempt to codify the succession of State responsibility failed largely because the project sits in an awkward crevice of history, where the 19th-century principle has collapsed without being replaced by consistent and universal practice of automatic succession. This post further challenges the rhetoric justifying the development, with particular attention to the interests of newly-independent nations.

Two implications follow beyond the topic. The first is methodological, and concerns the codification where practice available is predominantly context-specific treaties. While treaties ‘establishing similar rights and obligations’ covering a ‘broad array of States’ can serve as evidence of customary norms, the context of negotiation speak more than their provisions. (A/73/10 144-46) The second concerns international wrongs more broadly. For those endorsing automatic succession, the failure to systematically overrule the principle of non-succession leaves grave violations unanswered and shocks the sense of justice. (pp. 336-37) Yet accountability does not hinge solely on the succession; even where a successor State is not directly responsible for the wrongful act itself, obligations of investigation, non-recognition and other remedial measures survive the rupture in statehood, and their breaches offer victims independent grounds of claim. (A/CN.4/719 [72]; A/56/10 52) That architecture is what the ILC has been developing in its 2026 session, in the reports on compensation for damages and due diligence, and in the inclusion of obligations erga omnes in its programme. Terminating the project does not foreclose accountability for the wrongs successor States inherit.

After all, an honest acknowledgement of the instability and immatureness of the present law remains the finest embodiment of the ILC’s ‘balanced and prudent’ approach. (A/CN.4/743 [9]) For a body ‘less exciting, less fashionable’ than other institutions, mapping a turn of history is itself a bold and memorable undertaking. (p. 23)