INTRODUCTION

Treaties have been concluded from the moment there were entities of whom it could be said that they engaged in international relations, and have been concluded in a variety of forms. It is well documented that the ancient Greek city states concluded treaties with each other on such things as access to courts or treatment of prisoners of war, while the Louvre museum in Paris has on display the so-called Amarna letters, pieces of correspondence (chiselled in stone tablets) from the fourteenth century bc by the rulers of Syria and Palestine to pharaoh Amenophis IV (better known perhaps as Akhenaton, husband of Nefertiti).

It was quickly discovered that such agreements are best considered as somehow giving rise to binding obligations: pacta sunt servanda. Anything else would have been counterproductive; there is little point in concluding agreements if the premise is that no binding force will ensue. The rule pacta sunt servanda is thereby an indispensable rule, a rule of natural law in the sense that without it no system of law can be conceived. Still, binding as treaties may be, for a long time it was thought expedient to underline the binding force of treaties by practical means. A particularly gruesome guarantee was the exchange of ‘witnesses’; individuals were held hostage until such time as the treaty had been performed. More innocent was the practice of invoking the help of superior powers; for a long time, treaty-making was formalized by means of an oath.