«COMPLIANCE WITH INTERNATIONAL ENVIRONMENTAL AGREEMENTS»The subject of the thesis is whether and why states comply with their international environmental commitments. Lately, several authors have suggested that noncompliance might be a result of lacking ability to implement the international commitments, rather than a deliberate act of defection. This suggests that a distinction should be made between willingness to comply and ability to implement. The thesis questions the fruitfulness of such a distinction.The thesis is organized as a casestudy of Norwegian compliance with The Convention on Long Range Transboundary Air Pollution. Even though evidence from one case offers limited possibilities for generalization, the Norwegian case was identified as having important characteristics with regard to theory-building.Three different theoretical models are applied in the analysis of the case. The first model attempts to explain the Norwegian policy as a result of rational cost-benefit calculation in accordance with the perception of the state as a unitary rational actor. The realist focus on narrow economic self-interest pointed to important determinants of the Norwegian policy, and proved to be a valuable starting-point for the analysis. However, some questions remained unanswered, and indicated that it was not always economic interests that were decisive for state policy. It was argued that attempts to quantify national interests and thus make precise predictions about state policy were delusive.The second model explores to what extent state autonomy is limited by societal constraints. In relation to the other two perspectives, the domestic policy approach operated at a different level. While realism and neoliberal institutionalism were somewhat opposed to each other, the domestic policy approach provided evidence that either supported or rejected assumptions made by the two other models. However, this approach proved to be most important for the examination of the distinction between willingness and ability.The last model examines the neoliberal institutionalists claim that international institutions induce better compliance with international environmental agreements. The analysis indicated that this theory might reflect a so far biased selection of empirical cases. It was argued that more attention to the originally leading states in international environmental negotiations would lead to a conclusion that international institutions were not independent actors, but rather tools for vested state interests.Finally, the distinction between willingness and ability was rejected, as it was not possible distinguish between them in empirical analysis. Furthermore it was argued that it would not be possible to define objective criteria for when states could argue that their attempt to comply has failed, and thus claim that they were unable to implement their commitments.The thesis concludes that more attention should be paid to states' original motivation for entering into international environmental agreements. So far, the tendency in research has been to assume that the motivati on behind an international environmental treaty is always environmental concerns, and that there is some international proenvironmental will inducing countries to comply. The thesis demonstrated that this is not necessarily the case. Any attempt to make predictions about compliance with the agreement will thus have to consider the original motivations of the participating countries.