Introduction

One of the classic branches of international law is the law of immunity. States, their (political) leaders and their diplomatic representatives claim, and are usually granted, privileges and immunities in their mutual relations. Diplomats cannot, generally, be sued unless their immunity is waived, and diplomatic agents are exempt from certain forms of taxation and civil duties in the state where they are accredited. Moreover, diplomatic missions and belongings are generally inviolable. As far as the privileges and immunities of diplomatic agents go, these are usually explained with the help of the theory that, without immunities and privileges, diplomats cannot freely do their work. If a diplomat risks being arrested on frivolous charges at the whim of the host state, international relations can hardly be maintained. Some observers speak therefore of a theory of ‘functional necessity’ as underlying the granting of privileges and immunities to diplomatic agents and others in the service, but this terminology is less than fortunate.

States and their leaders can also boast some privileges and immunities, most important among these being the immunity from suit in the courts of a foreign state, at least for acts which may be qualified as governmental (acta jure imperii) rather than commercial (acta jure gestionis). Here, however, a ‘functional necessity’ theory is already less convincing, and it would seem that sovereign immunity is largely based on the idea that states require a space for the conduct of unencumbered politics without fear of legal ramifications, rather than on functional necessity.