Martić claimed that his actions were in response to persecution of the Serb population by the Croatian authorities.  Accordingly, he submitted defences of reciprocity or tu quoque; reprisal; and self-defence. 

Similarly, the Appeals Chamber found that self-defence could not be used to justify deliberately targeting a civilian population.

268. As for Martić’s alternative argument that the shelling of Zagreb was a lawful military action conducted in self-defence,[1] the Appeals Chamber recalls that “whether an attack was ordered as pre-emptive, defensive or offensive is from a legal point of view irrelevant […]. The issue at hand is whether the way the military action was carried out was criminal or not.”[2] […] As Martić has failed to show any error in the Trial Chamber’s conclusion that he deliberately targeted the civilian population of Zagreb,[3] his argument that the shelling of Zagreb was conducted in self-defence must fail. The Appeals Chamber takes note of Martić’s arguments in his concluding statement at the appeal hearing that “the Serbs were not aggressors but rather defended themselves in a situation when the United Nations made no attempt to protect them […].”[4] However, in particular in light of the fact that the prohibition against attacking civilians is absolute,[5] the Appeals Chamber fails to see how this claim could justify Martić’s actions in relation to the shelling of Zagreb.