Therefore, when violations occur, they are often resolved by communication between states, diplomatic maneuvers, or other amicable means. This also applies to environmental issues; it is probably true that most environmental concerns are resolved in a concerted and cooperative manner between states and interested parties.
However, this is not always the case. States have and will continue to take unilateral measures to enforce environmental policies they believe are beneficial for the condition of the environment or for other political or economic reasons. Many of these unilateral measures are legal per se either because they do not affect rights owed to other states, or because they are directly authorized by the relevant regime as derogation from its general obligations or as part of its enforcement mechanism. The countermeasures doctrine addresses the legality of one of many categories of unilateral measures, namely, those that are not directly justified by the relevant regime but seek their justification in the customary international law of countermeasures.
(B) A Prelude to the Law of Countermeasures
Countermeasures can be defined as any unilateral measures taken by states as a response to hostile or unfriendly acts of another state regardless of whether the unilateral measures taken are legal per se or require a special justification. Such approach, which might be suitable for consideration of the political justification of the measures or for analysis under theories of international relations, is too broad to be of any use for legal analysis. In other words, there is no need to analyze the legality of measures that are already legal. As this book’s main topic is the legal analysis of the countermeasures doctrine, it is logical to use the concept in a narrow meaning, covering only unilateral measures that are illegal per se but are justified as a response to an internationally wrongful act of another state. This approach is also in line with international jurisprudence, mainstream scholarly writing, and the work of the International Law Commission (ILC) on state responsibility.