Trade, foreign policy, diplomacy and health

7. International Law

David P Fidler

Sources of international law

  • Customary international law (CIL) governs day-to-day practical interactions of states, but unresponsive to new problems
  • ‘General principles of law recognized by civilized nations’ is not widely used
  • Treaty law thus predominant form of international law with respect to GPGH:
    • can create institutions and rules to directly address global problems BUT sensitive to sovereignty

International law is often associated with treaties, even though two other important sources of international law are customary international law (CIL) and "general principles of law recognized by civilized nations".

Historically, rules governing day-to-day practical interactions of states develop through CIL, producing various GPGs (eg diplomatic intercourse). However, CIL is often not responsive to new problems, such a CDC in 19th century, so states turn to treaty law to create new rules. Even where CIL exists in a public health context, states need treaty law to advance the GPG in question. Eg states have a CIL to conserve natural resources, but CIL also recognizes that states have sovereignty over exploitation of their natural resources so the 2 CIL’s conflict, and treaty is required to balance them. The "general principles of law recognized by civilized nations," is not used much in any context, so does not concern us here.

The importance of treaty law has positive and negative effects for the production of GPGs. Positively, states can use treaties to create institutions and specific rules that directly address global problems. The formation and interpretation of treaties is also a well-defined area of international law, which makes working with treaties easier than with CIL. On the negative side, treaties are the source of international law that is most sensitive to sovereignty. States are not bound by treaties unless they give their affirmative consent to be bound. By contrast, rules of CIL are universally binding on all states except those that persistently object to the rule, which has proved a difficult exception to meet. States often refuse to join treaties designed to produce GPGs, or withhold their consent until treaty obligations are diluted such that joining the treaty imposes less onerous burdens.