Inconsistency versus consistency in humanitarian intervention policy

While constructivist perspective in International Relations argues that humanitarian interventions are becoming more common, the realists believe that the international community intervenes selectively, preserving the interests of great powers. Given that humanitarian interventions are the result of political, military and financial negotiations of the states involved, it becomes difficult to explain empirically the endeavors of the European Union (EU) or the international community when facing humanitarian crises. Can we speak about a model of intervention, a normative constant regarding EU and international responses to humanitarian crises?