We have had a very rich debate on secession on the blog in recent weeks, and we will have more posts to follow. For my part, I would agree with much of what Jure Vidmar has said in his post this week, with the proviso that I personally don’t think the argument out of comparative constitutionalism necessarily has much purchase – that argument is contextually specific, and what works constitutionally in Canada or in the UK need not be the position in Spain. The ultimate arbiter of the Spanish constitutional order – the Constitutional Tribunal – has (for good or ill) not gone the Quebec Reference path. I agree in particular that international law has little to say on the secession of Catalonia specifically; Kurdistan is a more difficult question (on which a bit more below). What I would like to do in this post, however, is take a step back and reflect more generally on how secession is regulated by international law – and it is indeed regulated, if not wholly so.
It seems to me most useful to conceptualize international law’s regulation of secession in a three part model. First, there are cases where international law explicitly prohibits secession, when it is being effected through the violation of some fundamental norm of international law, such as the prohibition on the use of force or the prohibition on racial discrimination – this was the case, for example, with the Turkish Republic of Northern Cyprus. Such fundamental illegality is an impediment to the achievement of statehood which otherwise satisfies the relevant factual criteria, and thus bounds effectiveness. Crucially, as the ICJ has confirmed in the Kosovo AO, among these norms is NOT the principle of territorial integrity insofar as it does not govern the relationship between the parent state and an internal secessionist movement; that principle is only relevant if a third state assists a secessionist entity, as with Turkey and the TRNC.
Second, there is a middle ground, a zone of tolerance, where international law is neutral towards secession, neither prohibiting it nor creating a right to it. This neutral zone is what is left over from the classical position towards secession in international law, which was essentially that in order to establish itself as a state against the wishes of its parent, the secessionist entity needed to fight – and win – a war of independence against its parent (e.g. the USA, or most of the states of Latin America).
Finally, in the third part, a zone of entitlement, international law creates a right to secession under external self-determination, or perhaps remedial secession. The argument of Serbia and most of its allies in the Kosovo advisory proceedings was essentially that no zone of tolerance existed between prohibition and entitlement; the argument of Kosovo and its supporters that international law at the very least tolerated the declaration of independence/secession. Serbia could also have argued that even if the territorial integrity principle did not generally prohibit non-state actors from declaring independence, it did so here because Kosovo’s independence was as a matter of fact enabled by an unlawful use of force contrary to the Charter by NATO in 1999. Serbia of course deliberately chose not to do so, and for three basic reasons: it did not want to antagonize the NATO powers, as this argument would inevitably do, the Resolution 1244 regime came after the initial use of force and authorized the presence of international forces in Kosovo, and it was highly unlikely that the Court would want to rule on it in the context of the advisory proceedings.