[Larry Helfer is the Harry R. Chadwick, Sr. Professor of Law Professor of Law at Duke University School of Law]
I am delighted to participate in this
Opinio Juris book symposium on Jeff Dunoff and Mark Pollack’s excellent edited volume. My chapter on “
Flexibility in International Agreements” was improved by their many helpful comments and suggestions. This brief post summarizes a few of the chapter’s major themes. Citations to all references can be found in the online and print versions of the chapter.
Government officials, international lawyers, and diplomats have long been interested in shaping the form and content of treaties to manage the risks of international cooperation. These actors have responded to these risks with an diverse array of flexibility mechanisms, including unilateral reservation and declaration clauses; entry-into-force requirements; limitations on territorial application; duration provisions; amendment and revision procedures; and rules governing suspension, withdrawal, and termination.
In addition to these formal mechanisms, a range of informal practices can enhance the flexibility of treaties. Such practices include ad hoc supplementary accords, understandings, traditions, conventions, gentleman’s agreements, de facto modification of treaty obligations through conduct, auto-interpretation of ambiguous terms, and nonparticipation in treaty activities.
A principal challenge facing treaty negotiators is to select an appropriately constrained suite of flexibility mechanisms that facilitate agreement among states
ex ante while deterring opportunistic uses of those mechanisms
ex post after the treaty enters into force. Flexibility tools that are too easy to invoke will encourage self-serving behavior and lead to a breakdown in cooperation. Tools that are too onerous will discourage such behavior, but may prevent the parties from reaching agreement in the first instance, or, if agreement is reached, may lead to widespread violations if the costs of compliance increase unexpectedly.
Over the last decade, international law and international relations scholars have devoted growing attention to treaty flexibility tools.