International cooperation is at the core of every MEA. Simply put, MEAs would not exist if nations had not come together and agreed to adopt international law that governs a particular environmental issue or resource. Although action at the national level is vital for the implementation and enforcement of MEAs, these agreements constitute international law so the potential for nations to share experiences, approaches and policies for their implementation are myriad. No nation needs to stand alone in its efforts to comply with and enforce an MEA, because so many nations are Parties to each MEA.
It is true of all global and regional treaties that their international nature provides many opportunities for cooperation among States. Environmental agreements, however, have an added element that makes them particularly adaptable to international approaches: the problem or medium that is being addressed by the agreement is typically international in nature. Problems such as ozone depletion, biodiversity loss, transboundary movements of hazardous waste or endangered species, manufacture and use of bioaccumulating hazardous substances (such as persistent organic pollutants), and so forth are frequently global in nature.
To effectively manage a problem that is inherently global, global solutions must be applied. Similarly, bilateral or multilateral challenges associated with the migration of species across one or more national border requires transboundary solutions, albeit not necessarily at the global level.
Opportunities for international cooperation and coordination are myriad. Not only are there a large number of international organisations whose function is to facilitate such cooperation (for example, UNEP), but there is great potential for regional cooperative efforts, formal and informal bilateral contacts, NGO-driven efforts, and countless other cooperative initiatives (both official and unofficial). Training programmes, efforts to ensure legal and institutional consistency, judicial coordination, and capacity-building efforts are just a few areas in which international cooperation can improve the effectiveness of MEA compliance and enforcement.