This Chapter focuses on the situation where acts by the rebels or the government are committed in the context of the insurgent’s struggle for the creation of a new State. When the rebels are successful, the new State is not responsible for the acts committed by the predecessor State while fighting the rebels. The rule is problematic is however when the predecessor State ceases to exist. Also, the acts committed by the rebels during the insurgency are attributable to the new State after their victory. The rule applies in situations of secession, dissolution and Newly independent States, but it is controversial regarding transfer of territories. When the rebels are not successful, the acts committed by them are not attributable to the State once the insurgency has failed. Responsibility arises as a result of a State’s failure to discharge its due diligence obligation of vigilance, prevention and punishment in relation to the conduct of rebels.