In war military necessity to some extent justifies breaches to some international humanitarian law rules. However, there is no justifiable causes for breaching rules with the objective to reduce humanitarian suffering. Professor Gabriella Blum is the creator of the humanitarian necessity theory which investigates the possibility for humanitarian necessity as a ground for freedom from responsibility in armed conflicts.  By applying the humanitarian necessity theory to the Moscow Theater Hostage Crisis case this thesis strives to investigate how a humanitarian necessity theory would affect international humanitarian law on an operational level of war.  The result of the analysis shows that the theory would weaken existing international humanitarian law and have high risks of blurring the limits between legitimate targets and protected persons. The implementation of the theory could result in creating an even more complex environment where the humanitarian necessity theory causes negative humanitarian effects instead of decreasing humanitarian suffering.