Does 19 + 11 Equal 30?: the Nitty Gritty of the Law of Treaties and the Kampala Amendment to the Rome Statute on the Crime of Aggression

Sometimes, it seems that it is the reality of international law that provides one with questions of treaty law that probably even a sophisticated international law professor would have had problems inventing.

On November 19, 2014, San Marino became the 19^th State to have ratified the amendments to the Rome Statute on the crime of aggression. At the same time, Art. 15^bis, para 2 and Art. 15^ter, para. 2 of the Rome Statute in identical terms provide that “[t]he Court may exercise jurisdiction only with respect to crimes of aggression committed one year after the ratification or acceptance of the amendments by thirty States Parties” and further provided that under Art. 15^bis, para. 3 and Art. 15^ter, para. 3 respectively, a decision has been adopted by the Assembly of States Parties to activate the Court’s jurisdiction concerning the crime of aggression, such decision to be taken at the earliest in 2017.

What is worth noting, however, is that by now there are also eleven States, namely Cabo Verde, Côte d’Ivoire, Grenada, Guatemala, the Maldives, the Phillipines, St. Lucia, Tunisia, Vanuatu, Moldova and the Seychelles that have ratified the Rome Statute after the Kampala amendment on the crime of aggression was adopted. All of those States, when ratifying the post-Kampala Rome Statute, did so without expressing an intention not to be bound by the treaty as amended. This raises the intriguing question whether 19 + 11 equal 30, i.e. whether these new contracting parties ought to be counted towards the quorum required, as mentioned, by Art. 15^bis, para 2 and Art. 15^ter, para. 2 of the Rome Statute in order for the Court to exercise its jurisdiction.

While this question might, at first glance, be perceived as a mere academic and hypothetical glass bead game, it might as early as 2017 become practically relevant provided that by then the number of ratifications of the Kampala amendment on the crime of aggression as such will not yet have reached the threshold of 30. Such situation might very well occur given that the momentum by which current contracting parties have ratified the Kampala amendment ever since its adoption in 2010 has been rather slow, amounting to less than five ratifications per year.

The question, which would then accordingly arise, is whether the then contracting parties, meeting in the Assembly of States Parties of the Rome Statute, would nevertheless be in a position to activate the Court’s jurisdiction with regard to the crime of aggression thanks to San Marino’s 19^th ratification of the Kampala amendment in conjunction with the, so far, eleven post-Kampala ratifications of the Rome Statute.

In that regard it is first worth recalling that preambular paragraph 3 of RC/Res.5, adopted during the diplomatic conference and dealing with the amendments to article 8 of the Rome Statute, i.e. the inclusion of the war crime of using prohibited weapons in non-international armed conflicts specifically “[c]onfirm[ed] that, in light of the provision of article 40, paragraph 5, of the Vienna Convention on the Law of Treaties, States that subsequently become States Parties to the Statute will be allowed to decide whether to accept the amendment contained in this resolution at the time of ratification, acceptance or approval of, or accession to the Statute”. At the same time, resolution RC/Res 6, dealing with the crime of aggression, and simultaneously adopted in Kampala, does not contain a parallel provision to the same effect. Yet, given that the principle underlying Art. 40, para. 5 of the Vienna Convention on the Law of Treaties, to which RC/Res.5 had made reference, has codified customary law on the matter, the very same principle also applies with regard to the amendment on the crime of aggression, the lack of any specific reference to Art. 40, para. 5 Vienna Convention on the Law of Treaties in RC/Res 6 notwithstanding.

If that were true, this then however raises the further question, whether those States that have ratified the Rome Statute after the adoption of the amendment on the crime of aggression at the Kampala conference have, to use the formula contained in Art. 40, para. 5 of the Vienna Convention on the Law of Treaties, “become parties to the treaty after the entry into force of the amending agreement”.

Yet, for one, the enabling resolution adopted in Kampala, RC/Res 6 itself provides that the amendment on the crime of aggression “shall enter into force in accordance with article 121, paragraph 5”, i.e. by virtue of the very first ratification of the amendment, albeit for the States concerned only. Besides, Art. 15^bis/^ter, paragraph 2 both provide, as shown, that the Court will, subject to a further decision of the contracting parties, be able to exercise its jurisdiction once more than 30 States have “ratified or accepted” the amendment. This alternative wording implies that there are other ways of becoming bound by the amendment, than solely by way of ratification. Accordingly, it seems that States that have ratified the Rome Statute after the adoption of the Kampala amendment on the crime of aggression ought to be counted towards the quorum laid down in Art. 15^bis/^ter, paragraph 2 unless they, in line with Art. 40, para. 5 of the Vienna Convention on the Law of Treaties, have expressed a different intention. This result also stands in line with the object and purpose of Art. 15^bis/^ter, paragraph 2 of the Rome Statute, namely to only provide for the entry into force of the amendment provided once a sufficient high number of States have expressed their consent, one way or the other, to be bound by the amendment.

Accordingly, it indeed seems to be true that 19 + 11 equal 30 and that, by the same token, the Kampala amendment to the Rome Statute on the crime of aggression has, for good or for bad, now come a significant step closer to its entry into force – and with it the complex legal questions, to say the least, raised by the way the Rome Statute was amended at the first place.

At the same time, it is somewhat telling and, provided one shares the views taken here, misleading, that the Press Communiqué of the ICC distributed on the occasion of San Marino’s ratification of the amendment on the crime of aggression states that “[t]he Court may exercise jurisdiction over the crime of aggression once thirty States Parties have ratified the amendments” instead of using the more precise ‘ratified or accepted’ formula used in Art. 15^bis/^ter, para. 2.