In response, one starting point for the petitioners could be to challenge the very assumption upon which the respondents base their case, namely that the onus is on the petitioners to identify an international legal norm permitting the assertion of universal civil jurisdiction.
For this purpose, the petitioners could argue that rather than requiring the petitioners to identify the existence of a permissive rule, international law places the onus on the respondents to identify a prohibitive rule. Pursuant to this theory, an assertion of universal civil jurisdiction by the US courts would be presumed lawful so long as a prohibitive rule of international law to the contrary had not crystallised.
It is conceded that in the Arrest Warrant case, Judges Higgins, Kooijmans and Buergenthal noted that the “very broad form of extraterritorial jurisdiction [under the ATS] […] has not attracted the approbation of States generally”. For example, in the US Supreme Court case of Sosa v Alvarez Machain (“Sosa”), the UK, Switzerland and Australia protested to the jurisdiction of the US courts, while in Kiobel, the UK, the Netherlands and Germany all submitted briefs in support of the respondents.
However, it would be open to the petitioners to point out that the assertion of broad forms of jurisdiction under the ATS has equally not attracted the criticism of States generally. For example, in Filartiga v Pena-Irala, a case concerning a claim for damages for alleged torture of a Paraguayan national by a Paraguayan police official, Paraguay did not object to the jurisdiction of the US courts. In Kiobel itself, the US government submitted a brief in support of the petitioners.
In this light, the response of States to the exercise of universal civil jurisdiction under the ATS may best be characterised as mixed, and certainly insufficiently uniform to crystallise into a prohibitive rule. With this in mind, the petitioners could assert that in the absence of such a prohibitive rule, the exercise of universal civil jurisdiction by US federal courts is lawful under international law.
The basis for this approach may be traced back to the following dictum of the Permanent Court of International Justice in the Lotus case:
“Far from laying down a general prohibition to the effect that States may not extend the application of their laws and the jurisdiction of their courts to persons, property and acts outside their territory, it [international law] leaves them in this respect a wide measure of discretion which is only limited in certain cases by prohibitive rules; as regards other cases, every State remains free to adopt the principles which it regards as best and most suitable.”
The Lotus dictum is attractive for the petitioners since it purports to place the viber database burden of proof on the respondents to identify a prohibitive rule. Yet, for all its attractiveness, it is submitted that the Lotus dictum is ultimately unpersuasive for two reasons.
First, the Lotus approach does not reflect State practice. In particular, as noted by Lowe and Staker, in over a century of objections to exercises of universal jurisdiction, there does not appear to be a single instance of an objecting State seeking to prove the existence of a prohibitive rule forbidding assertions of universal jurisdiction:
“When States object to exercises of jurisdiction, they simply assert that the other State has ‘no right’ to exercise jurisdiction in the way that it claims. State practice is consistently based upon the premiss that it is for the State asserting some novel extraterritorial jurisdiction to prove that it is entitled to do so.