Diplomacy is a highly complex, multifaceted and often unpredictable profession. By definition, it seeks to overcome differences between and among countries, and those distinctions run the risk of turning into discord, or even conflict, without a playing field that has mutually accepted rules and norms. This is the role of diplomatic protocol, a system of standards, rules and regulations governing the conduct of international relations. It brings order and predictability to the work of diplomats by providing a roadmap or framework, so they can focus on the substance of negotiations and high-stakes decisions. It has been called “the oil in the gears of diplomacy” and credited with creating a “safe space that allows diplomacy to succeed.” While tradition has always had a special place in diplomacy, protocol’s role is hardly limited to old-fashioned pomp and circumstance. It has practical aspects meant to make diplomatic work more effective.

In the late 1980s, a winding series of drug trafficking charges against the then de facto leader of Panama, General Manuel Noriega, led the US government to seek his arrest, following a controversial military intervention into Panama, and trial before a US court. The rejection of his entitlement to foreign official immunity by the US District Court for the Southern District of Florida (a verdict affirmed by the Eleventh Circuit Court of Appeals) culminated in an unprecedented decision at the time – long-term imprisonment of the Panamanian strongman in the United States. Not only did the Noriega court pave the way for subsequent prosecutions of top-tier state officials involved in drug trafficking in the United States, but it also brightly reverberated in the scholarly writing of successive decades concerning matters of head-of-state immunity. It also gained international notoriety and was hailed to be a “triumph for diplomacy and a triumph for justice.”

The then ICJ Judge Awn Shawkat Al-Khasawneh defined immunity “[as] … an exception from the general rule that man is responsible legally and morally for his actions.”1 While it is widely acknowledged that serving high-ranking public officials enjoy immunity from the jurisdiction of foreign courts in most circumstances, there is an ongoing debate regarding how far the immunity entitlement extends and whether there are exceptions to it, particularly in cases of serious criminal wrongs. The present chapter reviews the conceptual, doctrinal, and theoretical foundations of the immunities of foreign officials, and their subjective, material, and temporal scopes. It also examines the rules that govern situations when foreign official immunity may not apply or may apply only to official acts, and the conditions for either of these outcomes. The chapter draws from recent developments in international criminal law, international human rights law, and transnational criminal law, and builds on the influential contribution of the ILC on the topic “Immunity of State Officials from Foreign Criminal Jurisdiction” included in the long-term program of work of the commission in 2006.

The previous chapter described the extent of a state’s physical territory; this chapter looks at how far a state’s legal power extends. As will be seen, international law places certain limits on the right of a state to make, apply and enforce its laws – its jurisdiction – and these limits are considered in Section 6.2. International law also recognises two principal bars to the exercise of that jurisdiction: diplomatic immunity and state immunity; these are covered in Sections 6.3 and 6.4. Two other bars to jurisdiction, namely special mission immunity and the foreign act of state doctrine, are also briefly covered in Sections 6.6 and 6.7.

How do states create agreements with one another, and how do they ensure they are followed? The first half of this chapter details the process by which states make, maintain, and rescind treaties. We elaborate on the treaty process set forth in the Vienna Convention on the Law of Treaties, and explain different treaty types (e.g., bilateral vs. multilateral, self-executing vs. non-self-executing). Reservations—portions of a treaty a state does not wish to join—are also discussed, as well as their ramifications. The second half of the chapter establishes the centrality of diplomats to the creation and execution of much of international law, including treaties.  We elaborate on diplomatic and consular functions as well as diplomatic immunity and asylum.  Diplomats are noted as change agents in the international system, but the potential for abuse of that immunity is always present.

International law on immunities consists of a body of procedural rules that limit when a state may exercise jurisdiction within its territory. These procedural rules could prevent a domestic court from exercising jurisdiction in a case involving a foreign state, a foreign state official, or an international organization. These rules could also prevent a police officer from exercising jurisdiction by arresting and detaining a foreign diplomat or a minister of foreign affairs. International law bars the exercise of jurisdiction in such situations, either because the exercise of jurisdiction would threaten the equality of sovereign states or because the capacity of the individual or organization to carry out their functions would be compromised. This chapter begins with the law on state immunity, which has evolved over the centuries from an absolute doctrine to a more restrictive one, which permits exceptions, in particular when states engage in commercial activities. The chapter introduces the immunities that apply to all individuals who serve as state officials, whether they serve as relatively low-level civil servants or as the president or prime minister. The chapter also deals with two special regimes, one governing diplomatic and consular agents who serve abroad, and the other governing international organizations.

International law on immunities consists of a body of procedural rules that limit when a state may exercise jurisdiction within its territory. These procedural rules could prevent a domestic court from exercising jurisdiction in a case involving a foreign state, a foreign state official, or an international organization. These rules could also prevent a police officer from exercising jurisdiction by arresting and detaining a foreign diplomat or a minister of foreign affairs. International law bars the exercise of jurisdiction in such situations, either because the exercise of jurisdiction would threaten the equality of sovereign states or because the capacity of the individual or organization to carry out their functions would be compromised. This chapter begins with the law on state immunity, which has evolved over the centuries from an absolute doctrine to a more restrictive one, which permits exceptions, in particular when states engage in commercial activities. The chapter introduces the immunities that apply to all individuals who serve as state officials, whether they serve as relatively low-level civil servants or as the president or prime minister. The chapter also deals with two special regimes, one governing diplomatic and consular agents who serve abroad, and the other governing international organizations.