Germany Joins the Campaign against ISIS in Syria: A Case of Collective Self-Defence or Rather the Unlawful Use of Force?

Abstract

On December 4, 2015, the Bundestag agreed to the participation of German troops in the Western-led military campaign against the so-called Islamic State or ISIS in Syria. This article will discuss whether the military campaign Germany is now supporting is justified under international law. The main argument put forward by the German Government is that the use of force against ISIS targets in Syria is justified based on UN Security Council Resolution 2249 (2015) and Art. 51 of the UN Charter. Germany thus seems to be claiming that it is engaged in collective self-defence against ISIS in support and at the request of Iraq and France. It will be shown that this line of argument is not convincing. Resolution 2249 does evidently not authorize the use of force. Article 51, on the other hand, while explicitly permitting the use of force in response to an armed attack, is limited to attacks imputable to another state. ISIS, however, is neither a state, nor is it directed by a state. Having found the German Government’s arguments to be unpersuasive, the article will then turn to customary international law as a possible source of justification. Has customary international law, especially in the aftermath of the use of force against Afghanistan under the Taliban in the aftermath of 09/11, evolved in such a way so as to now permit the use of force in self-defence against non-state actors on another state’s territory without that state’s consent? Based on state practice prior and subsequent to Afghanistan it will be shown that customary international law does currently not justify the Western-led military campaign against ISIS in Syria. Bearing in mind that Syria’s Government, in contrast to the Afghan Taliban Government’s attitude towards Al-Qaeda in 2001, is itself attempting to fight ISIS, it must therefore be concluded that Germany’s participation in the Western-led military campaign is unlawful.