IL/IR Symposium: Flexibility in International Agreements

[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. For example, studies have analyzed duration (Koremenos 2005), reservations (Goodman 2002; Swaine 2006; Neumayer 2007; Miles and Posner 2008; Kearney and Powers 2011), membership and voting rules (Goodman and Jinks 2004; Helfer 2008), framework conventions and protocols (Setear 1999), soft law (Guzman and Meyer 2010l Shaffer and Pollack 2010), delegation to international organizations (Alvarez 2005; Helfer 2006; Guzman and Landsidle 2008) and to international tribunals (Guzman 2002, 2008; Helfer and Slaughter 2005; Posner and Yoo 2005), escape clauses (Gross and Ní Aoláin 2006; Sykes 1991; Rosendorff and Milner 2001; Neumayer 2011), exit provisions (Helfer 2005; Koremenos and Nau 2010; Meyer 2010), and the relationship between treaty form and substance more generally (Guzman 2005; Hathaway 2005; Raustiala 2005). Flexibility also figures prominently in the rational design literature, most notably in the 2001 special issue of International Organization (Koremenos et al. 2001).

These studies suggest three general conclusions about how flexibility tools promote or inhibit interstate cooperation.  First, the studies support a central claim of rational design scholars – that governments manage the risks of international cooperation not only by adjusting a treaty’s substantive standards and its membership rules, but also by selecting from among an array of flexibility devices. The studies also suggest that states make tradeoffs among potentially available flexibility tools in an attempt to calculate an overall level of treaty risk.

These conclusions do not, however, rule out the possibility that certain types of flexibility mechanisms are not designed, or designed rationally. In fact, a second general conclusion of the literature is that the use of flexibility mechanisms sometimes diverges from the expectations of a treaty’s drafters and the conjectures of rational design scholars. In some instances, the unanticipated behavior relates to how frequently governments invoke flexibility tools. In others, states with certain domestic characteristics – such as those with democratic or autocratic governments – are, contrary to predictions, the predominant users of particular flexibility devices. And, in still other cases, there are unanticipated interaction or substitution effects among formal and informal flexibility mechanisms.

These conclusions suggest four lines of inquiry that scholars might pursue in future studies. First, in addition to analyzing individual flexibility mechanisms, scholars should give greater attention to the relationship among different flexibility tools. Barbara Koremenos’ 2005 article, Contracting Around International Uncertainty, is a pioneer in this regard. Future studies might consider whether other flexibility tools are complements or substitutes. This research would be especially welcome for issue areas, such as environment and security, for which flexibility tools have received less attention.

A second promising avenue for research would consider when and how states actually exercise the formal and informal flexibility mechanisms available to them. Failure to address how flexibility tools actually function in practice risks two types of errors. On the one hand, treaties with few flexibility mechanisms (i.e., agreements that are sovereignty-restrictive on paper) may turn out to be far less constraining in fact, for example due to informal flexibility practices not reflected in treaty texts. Conversely, factors such as reputational concerns, asymmetric distributions of power, or entrenched behavioral norms may deter states from invoking flexibility clauses.

Third, future research could investigate how flexibility tools interact with the form and substance of international agreements. For example, scholars might consider how the number, type, scope, and combination of flexibility devices are influenced by four overarching constraints that treaty negotiators face: (1) a “participation constraint” that results from a desire to induce all states affected by a particular cooperation problem to join an agreement; (2) a “sovereignty constraint,” characterized by an aversion to delegating authority to international institutions, even where doing so provides an effective way to resolve transborder collaboration problems; (3) an “information constraint” caused by pervasive uncertainties relating to future events and the preferences of other states; and (4) a “problem structure constraint” that is a function of the externally determined features of a substantive issue area, such as its public goods or club goods character.

A fourth line of inquiry might probe whether flexibility mechanisms are especially appealing to – and most likely to be used by – particular types of domestic regimes. Several recent studies of human rights treaties find that democracies reserve and derogate more frequently than do other states (e.g., Hafner-Burton, Helfer & Fariss 2011). Scholars might consider whether the design and use of flexibility tools in other issue areas exhibit similar patterns and, if they do, develop and test hypotheses to explain these findings.