6. The Practical Working of the Law of Treaties

This chapter examines key structural questions and fundamental problems relating to the law of treaties. These structural matters include: the concept of a treaty; the anatomy of treaties (including the making of treaties; authority to conclude treaties; expression of consent to be bound; invalidity of treaties (non-absolute grounds for invalidity of treaties, absolute grounds for invalidity of treaties, amendment, and modification); suspension and termination). The key issues addressed include the scope of legal obligation (the principle pacta sunt servanda, treaties, and third States); interpretation and reservation to treaties (including interpretative declarations); and finally, problems concerning the grounds for termination (supervening impossibility and material breach). The chapter also considers the theory and practice of the law of treaties, with broad analysis of the case law of various international courts and tribunals, with special emphasis on jurisprudence of the International Court of Justice.