Earlier this week, Reuters reported that Gulf Arab States are considering arming militant groups in Syria to fend off Assad’s onslaught in Aleppo and elsewhere. There may be an unanticipated benefit to such actions: application of the full enforcement regime of the Geneva Conventions. In other words, with all the discussion these days about what to do about war crimes committed by Assad’s forces, the internationalization of the conflict may provide a unique opportunity to set in motion a global enforcement apparatus.

The key question under international law is whether the actions of the Gulf States would trigger an “international armed conflict.” Why is that classification of the conflict important? The answer is a hope of deterring or repressing Assad’s war crimes through a global war crimes enforcement regime. Under the Geneva Conventions, all States have an obligation to prosecute or extradite suspected war criminals who pass through their territory. Think what that might mean for Syrian officials, and the power it might hand States around the world in trying to change the incentives of Assad and his forces. This enforcement mechanism, however, applies only to war crimes committed in conflicts between two or more States (“international armed conflict”). It does not apply to non-international armed conflict. It is true that States may be entitled to prosecute war crimes committed in a non-international armed conflict, but there is no treaty compulsion for them to do so.

So would the measures reportedly being contemplated by the Gulf States, if put into action, trigger that Geneva Conventions’ enforcement regime? The threshold question is whether State X’s arming rebels in a fight against State Y triggers an “armed conflict” between the two States under the Geneva Conventions (common Article 2 of the Conventions, to be exact). Let’s start with two well-settled rules in international law:

  1. An international armed conflict exists whenever there is a resort to armed force between two or more States.
  2. As Mike Schmitt and I have explained in an earlier post, a State’s arming a militant group inside another State constitutes a “use of force.”

Despite those two widely accepted propositions, it is not as easy to answer the question whether the arming of rebels is the kind of “armed force” that triggers an international armed conflict.

Professor Schmitt has written elsewhere that arming and training rebels does not cross that line. He wrote: “even though military aid to rebels is a use of force, it does not alone initiate an armed conflict. International armed conflicts require ‘hostilities,’ a legal term of art, between states. … [N]o state has adopted the position that merely providing arms to rebels involved in a non-international armed conflict internationalizes an armed conflict, such that an armed conflict between the two states exists.”

On the other hand, in a landmark opinion by the International Criminal Tribunal for the Former Yugoslavia, the Presiding Judge, Mohamed Shahabuddeen issued a separate opinion which took the opposite view. He explained that he had “no difficulty” in concluding that Serbia’s arming a militant group in Bosnia-Herzegovina sufficed to show that Serbia “was using force through [the militant group]” against Bosnia-Herzegovina. On that basis, he concluded that the two States were in an international armed conflict for the purpose of applying war crimes provisions of the Geneva Conventions. Why did the judge have “no difficulty” in reaching that conclusion? He relied on an International Court of Justice (ICJ) opinion that addressed the United States’ arming rebels (the contras) in Nicaragua. Here’s the key passage from the ICJ’s opinion which Judge Shahabuddeen quoted:

“The conflict between the contras’ forces and those of the Government of Nicaragua is an armed conflict which is ‘not of an international character’. The acts of the contras towards the Nicaraguan Government are therefore governed by the law applicable to conflicts of that character; whereas the actions of the United States in and against Nicaragua fall under the legal rules relating to international conflicts.” (emphasis added).

We live in a world in which judges often interpret the law in ways to accommodate pressing policy concerns. When it comes to atrocities in Syria, judges may also find “no difficulty,” or at least not overwhelming difficulty, reaching a conclusion that the law of international armed conflict applies to the actions of Assad’s forces. If the conflict in Aleppo becomes internationalized, atrocities that are committed with a nexus to those hostilities could kick into action a whole set of legal rules with new implications for diplomatic negotiations and efforts at accountability.