80 INTERNATIONAL LEGAL PROTECTION OF HUMAN RIGHTS IN ARMED CONFLICT from their own responsibility of supervision and control. Yet, for command responsibility to be applicable, it is necessary that the superior knew or had reason to know that violations were being committed or were about to be committed. In that case, the superior is under the obligation to adopt all necessary measures to prevent such violations or punish the perpetrators if they do occur. The Appeals Chamber of the International Criminal Tribunal for the former Yugoslavia analysed the different components of the notion of command responsibility. It recalled that a commander’s de jure power creates a presumption of effective control. It also discussed the scope of the “had reason to know” standard and indicated that the commander’s responsibility would be engaged if he failed to act despite having sufficiently alarming information about possible violations. The Appeals Chamber indicated that “[w]hile a superior’s knowledge of and failure to punish his subordinates’ past offences is insufficient, in itself, to conclude that the superior knew that similar future offences would be committed by the same group of insubordinates, this may […] nevertheless constitute sufficiently alarming information to justify further inquiry”. Thus, it interpreted the “reason to know” standard as requiring an assessment of whether a superior had sufficiently alarming information that would have alerted him to the risk that crimes might be committed by his subordinates.116 In another case, the Tribunal’s Trial Chamber made it clear that the determination of a causal link between a commander’s failure to act and his subordinate’s crimes is unnecessary to a finding of superior responsibility. It recalled that “[i]f a causal link were required this would change the basis of command responsibility for failure to prevent or punish to the extent that it would practically require involvement on the part of the commander in the crime his subordinates committed”.117   Prosecutor v. Hadžihasanovic´ & Kubura, case No. IT-01-47-A, Judgement of 22 April 2008, in particular para. 30. 117   Prosecutor v. Sefer Halilovic´, case No. IT-01-48-T, Judgement of 16 November 2005, para. 78. 116