Ethics of Humanitarian Interventions

Humanitarian Interventions - that sounds nice; much nicer than wars, battles and use of military force. Foremost, the phrase makes you think of the delivery of sanitary goods, medication, of soup-kitchens. Here we are not supposed to think of interventions of this kind; we have to have humanitarian interventions in mind which are humanitarian intervention-wars. (I) At exactly what point is the use of military force a humanitarian intervention?