The Ljubljana-The Hague Convention: Where are we Now?

[Dr Alison Bisset is an Associate Professor in International Human Rights Law at the University of Reading School of Law]

The Ljubljana-The Hague Convention on International Cooperation in the Investigation and Prosecution of the Crimes of Genocide, Crimes Against Humanity, War Crimes and Other International Crimes was adopted in May 2023, creating a previously lacking global framework for inter-state judicial cooperation on international crimes. It is an important feature of a shifting international criminal justice landscape, in which there is a new focus on investigations and prosecutions at national levels. The ICC has launched a new policy under which it will operate as a ‘justice hub’, supporting national authorities. At the same time, record numbers of states are pursuing domestic trials of international crimes on the basis of universal and extraterritorial jurisdiction. The vital role of inter-state assistance has never been more apparent: a robust legal framework which enables states to request and share information and evidence, access victims, witnesses and assets, and extradite suspects is essential if states are to effectively prosecute international crimes. The purpose of the Ljubljana-The Hague Convention is to ensure that states have at their disposal these technical tools. 

One year ago, in February 2024, the Convention opened for signature. As this anniversary is reached, supporting states and NGOs are calling upon others to ratify the Convention.  This piece asks: what is the current status of the Convention and what progress has been made? It shows that while the Convention attracted an early flurry of signatures, progress has stalled and the Convention is currently dominated by European, ICC states parties.

The Treaty

The nature and development of the Ljubljana-The Hague Convention is well documented and will not be recounted at length again here. In brief, the Convention emerged from an initiative (the MLA Initiative) led by a group of core states (Argentina, Belgium, Mongolia, the Netherlands, Senegal and Slovenia) to develop a new treaty tackling the cooperation gap around international crimes. 

The final treaty comprises eight parts: (I) general provisions; (II) central authorities and communication; (III) mutual legal assistance; (IV) extradition; (V) transfer of sentenced persons; (VI) victims, witnesses, experts and other persons; (VII) institutional arrangements; and (IX) final provisions.  It applies to the core crimes of genocide (Article 5(1)), crimes against humanity (Article 5(2)) and war crimes (Article 5(4)), defined in accordance with the Rome Statute. States parties can opt under Article 2(2) to extend the Convention’s application to a range of other international crimes (torture, enforced disappearance, the amendments to war crimes under the ICC Statute and aggression), which are contained in a series of annexes (A-H). To date, Democratic Republic of Congo has declared that it will apply the Convention to all crimes in the annexes and Germany has declared intention to apply the Convention to annexes A, B, E, F, G and H, excluding application to war crimes involving weapons which injure by non-detectable fragments and blinding laser weapons.

Under the Convention, States Parties are required to criminalise treaty crimes in domestic law (Article 7) and establish universal jurisdiction of courts over Convention crimes where a suspect is present on their territory (Article 8). An aut dedere, aut judicare obligation is set down in Article 14. It also creates new protections for victims in judicial assistance proceedings (Part VI). The Convention is therefore ambitious in its efforts to bolster the ICC complementarity regime and close the loopholes which have enabled perpetrators of international crimes to evade justice in the past. While the ICC Statute’s silence on the obligations of states to enact implementing legislation led to much debate in academic circles, there is no such ambiguity in the Ljubljana-The Hague Convention. 

In terms of cooperation, which forms the most substantial component of the Treaty and was the impetus behind it, the Convention is a significant step forward. The essential elements of effective cooperation systems – the designation of central authorities (Article 20), channels and means of communication (Article 21), and language of requests, (Article 22) – are all provided for. On mutual legal assistance, states parties are required to provide each other with the widest measure of mutual assistance in investigations, prosecutions and judicial proceedings in relation to the crimes within the Convention (Article 23(1)). Also regulated are: the purposes for which assistance can be sought (Article 24); the format of requests (Article 25); grounds for refusal of assistance (Article 30); and procedures for execution of requests (Article 33). The Convention provides for the appearance of persons in the requesting state (Article 35), hearings by video conference (Article 34), and the deposition of witnesses in the requested state (Article 33). The use of special investigative techniques (Article 39), cross border observations (Article 42), covert investigations (Article 40) and the establishment of joint investigation teams (Article 41) are extensively regulated. 

On extradition, it provides protections under the rule of speciality (Article 52), formalities and procedures for requests (Articles 55-57), grounds for refusal (Article 51) and provisional arrest and transit (Article 59). It regulates re-extradition to third states (Article 53) and the receipt of conflicting requests (Article 58) and provides a mechanism for seizure and exchange of property (Article 64).

Current Signatures

Since 14 February 2024, when the Convention opened for signature, 37 states have signed it. Most of them did so as soon as the Convention was opened. None have yet ratified. Since February 2024, only three states have signed (Costa Rica and Mongolia in June 2024 and Cyprus in December 2024).

26 of the signatory states, more than 70 per cent, are European (Albania, Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Finland, France, Germany, Ireland, Liechtenstein, Lithuania, Luxembourg, Malta, Moldova, Montenegro, Netherlands, North Macedonia, Norway, Poland, Slovakia, Slovenia, Sweden, Switzerland, Ukraine). There are five African states (Central African Republic, Democratic Republic of Congo, Ghana, Rwanda and Senegal), four from Latin America and the Caribbean (Argentina, Chile, Costa Rica, Uruguay), and one from Asia (Mongolia). 

It is therefore currently a distinctly European treaty, and, perhaps unsurprisingly, one dominated by ICC States Parties. Only Rwanda is non-states party to the ICC. This largely mirrors the diplomatic negotiations that led to the adoption of the Convention. In May 2023, of the 80 Supporting States, more than half were European. There were none from the Middle East and only three from Asia. The MLA Initiative was dominated by ICC States Parties throughout; only 7 of the Supporting States were non-States Parties.

So far, it has been difficult to attract support beyond Europe. 

Reservations

Possibilities for reservation are regulated under Article 92. Reservations can be formulated in respect to three specific forms of cooperation (Article 92(2)): special investigative techniques (Article 39), covert investigations (Article 40) and cross border observations (Article 42). These are notoriously complex areas in which privacy, human rights and sovereignty concerns converge to impede inter-state cooperation. No signatory state has yet entered a reservation in relation to these provisions, although it is possible that reservations may be entered following ratification processes at national levels. 

Article 92(2) also permits States Parties to enter a declaration that they do not recognise the authority of the ICJ to resolve any dispute that arises between states parties (Article 86(3)). None has yet done so. The final ground for reservation under Article 92(2) relates to Article 90(5) and enables states not to apply the Convention to requests relating to acts or omissions that occurred before the date indicated by that State Party, provided that this date is no later than the entry into force of the Convention or the relevant annex. Germany has entered a reservation that it will not apply the Convention to acts or omissions that occurred before the entry into force of the Convention. 

Under Article 92(3) reservation is also possible in relation to Article 8(3) and the obligation to establish universal jurisdiction. It is documented that during the negotiations in Ljubljana, the UK and France proposed making the aut dedere, aut judicare obligations discretionary, arguing that international law is unsettled on whether the obligation applies to all of the crimes covered by the Ljubljana-The Hague Convention and its annexes. In order to reach consensus, Article 92(3) allows for a reservation to the obligation to establish universal jurisdiction set down in article 8(3) of the Convention. Koutroulis has pointed out that Article 92(3) does not allow states parties to exclude the exercise of universal jurisdiction, only to – as the article itself states – limit the establishment of jurisdiction. Indeed, France’s reservation under Article 92(3) explains that in relation to Article 8(3) France will only prosecute persons ‘habitually residing in its territory’, habitual residence being defined as a ‘sufficient connection with France’, which is judged on the facts. As required under Article 92(3), the French reservation is made for a renewable period of three years. 

Next Steps

The Core Group of the MLA Initiative has embarked upon a number of diplomatic measures to promote the Ljubljana-The Hague Convention and encourage ratification. In December 2024, the core group organised a side event on the Convention at the 23^rd Session of the ICC Assembly of States Parties, with speakers from the ICC, national prosecution services, NGOs and academia. A pledge, also led by states from the core group, has recently been adopted at the 34th International Conference of Red Cross and Red Crescent. Under the pledge, signatory states pledge to raise awareness of the potential of the Convention and encourage other states to sign it. So far, Belgium, Liechtenstein and Andorra have signed the pledge. The connected action plan consists of a series of measures to raise awareness of the Convention at international, regional and domestic levels amongst state and judicial actors. Progress is intended to be measured by numbers of signatures and ratifications, events and references to the Convention in documents adopted in national and international fora, as well as in the public domain. Interestingly, a separate pledge by the EU and its Member States on fighting impunity for international crimes, also lists ratification of the Convention in its action plan. The inclusive approach of the MLA Initiative also means that many NGOs are invested in the process and continue to use their platforms to call upon states to ratify. 

Concluding Remarks

In sum, the Ljubljana-The Hague Convention holds the potential to significantly improve the process behind national prosecutions of international crimes and make a real contribution to the fight against impunity. To realise that potential, states that have already signed the Convention must now ratify. Yet the real challenge lies in convincing states that have traditionally been reluctant to become involved in prosecuting international crimes to join the Treaty. In this, the core group must continue to work to combat any perception that the Convention is just a European venture working as an arm of the ICC and encourage global ratification of an important treaty development. 

Photo attribution: “Signing conference Ljubljana-The Hague Convention in the Peace Palace, 14 February 2024” by Netherlands Ministry of Foreign Affairs / Valerie Kuypers & Martijn Beekman is in the public domain