Recent developments in international environmental law are increasingly characterized by the concern with ensuring the effectiveness of existing international environmental obligations, as well as by a growing awareness of the need to adopt a comprehensive and integrated approach in the management of natural resources. Non-compliance mechanisms are generally assumed to be better than courts for achieving these aims. This chapter assesses this assumption through the analysis of the Gabčíkovo-Nagymaros and Bystroe Canal cases. Despite a judgment of the International Court of Justice (ICJ) in Gabčíkovo-Nagymaros and the triggering of non-compliance procedures in Bystroe Canal, both cases are still pending or have remained substantially unsettled. In particular, this chapter compares the approaches adopted by the ICJ and the competent monitoring bodies, evaluating their respective contributions to: balancing the parties’ conflicting interests; stimulating meaningful and fruitful co-operation of the parties towards an agreed solution; integrating the interests of the parties concerned with the interests of other States, individuals or group of individuals and the global environment.