Vienna Convention on Diplomatic Relations in the context of "Ambassador"

An apostolic nuncio (Latin: nuntius apostolicus; also known as a papal nuncio or simply as a nuncio) is an ecclesiastical diplomat, serving as an envoy or a permanent diplomatic representative of the Holy See to a state or to an international organization. A nuncio is appointed by and represents the Holy See, and is the head of the diplomatic mission, called an apostolic nunciature, which is the equivalent of an embassy. The Holy See is legally distinct from the Vatican City or the Catholic Church. In modern times, a nuncio is usually an Archbishop.

An apostolic nuncio is generally equivalent in rank to that of ambassador extraordinary and plenipotentiary, although in Catholic countries the nuncio often ranks above ambassadors in diplomatic protocol. A nuncio performs the same functions as an ambassador and has the same diplomatic privileges. Under the 1961 Vienna Convention on Diplomatic Relations, to which the Holy See is a party, a nuncio is an ambassador like those from any other country. The Vienna Convention allows the host state to grant seniority of precedence to the nuncio over others of ambassadorial rank accredited to the same country, and may grant the deanship of that country's diplomatic corps to the nuncio regardless of seniority. The representative of the Holy See in some situations is called a Delegate or, in the case of the United Nations, Permanent Observer. In the Holy See hierarchy, these usually rank equally to a nuncio, but they do not have formal diplomatic status, though in some countries they have some diplomatic privileges.

A chargé d'affaires (French pronunciation: [ʃaʁʒe dafɛʁ] ), plural chargés d'affaires, often shortened to chargé (French) and sometimes in colloquial English to charge-D, is a diplomat who serves as an embassy's chief of mission in the absence of the ambassador. The term is French for "person charged with business", meaning they are responsible for the duties of an ambassador. Chargé is masculine in gender; the feminine form is chargée d'affaires (pronounced the same way).

A chargé enjoys the same privileges and immunities as an ambassador under international law, and normally these extend to their aides as well. However, chargés d'affaires are outranked by ambassadors and have lower precedence at formal diplomatic events. In most cases, a diplomat serves as a chargé d'affaires on a temporary basis in the absence of the ambassador. In unusual situations, in cases where disputes between the two countries make it impossible or undesirable to send agents of a higher diplomatic rank, a chargé d'affaires may be appointed for an indefinite period.

United Nations General Assembly Resolution 1668 (XVI) was an act of the UN General Assembly that deemed the issue of Chinese representation at the UN an "important question" under the UN Charter; therefore any proposal to change of recognition either to the People's Republic of China from the Republic of China and designated as such as the representation of all of China at the UN would hence require a two-thirds majority of all voting members. The impetus for UN Resolution 1668 (1961) was raised by Australia, Colombia, Italy, Japan, and the United States and passed with 61 UN Member States voting in its favor, 34 UN Member States voted against it, 7 UN Member States abstaining, and 2 UN Member States non-voting. The Vienna Convention on Diplomatic Relations was signed by the Republic of China on 18 April 1961 and ratified on 19 December 1969. The Vienna Convention on Diplomatic Relations is the cornerstone of modern-day diplomacy since the Vienna Congress and followed by the UN.

The Iran hostage crisis (Persian: بحران گروگانگیری سفارت آمریکا) began on November 4, 1979, when 66 Americans, including diplomats and other civilian personnel, were taken hostage at the Embassy of the United States in Tehran, with 52 of them being held until January 20, 1981. The incident occurred after the Muslim Student Followers of the Imam's Line stormed and occupied the building in the months following the Iranian Revolution. With support from Ruhollah Khomeini, who had led the Iranian Revolution and would eventually establish the present-day Islamic Republic of Iran, the hostage-takers demanded that the United States extradite Iranian king Mohammed Reza Pahlavi, who had been granted asylum by the Carter administration for cancer treatment. Notable among the assailants were Hossein Dehghan (future Minister of Defense of Iran), Mohammad Ali Jafari (future Commander-in-Chief of the Islamic Revolutionary Guard Corps), and Mohammad Bagheri (future Chief of the General Staff of the Iranian Armed Forces). The hostage crisis contributed to a dramatic decline in Iran–United States relations. After 444 days, it came to an end with the signing of the Algiers Accords between the Iranian and American governments; Iran's king had died in Cairo, Egypt, on July 27, 1980.

The American magazine Time described the Iran hostage crisis as an entanglement of vengeance and mutual incomprehension. American president Jimmy Carter called the hostage-taking an act of "blackmail" and the hostages "victims of terrorism and anarchy." Among proponents of the Iranian Revolution, it was seen as an act against perceived attempts by the United States to undermine the uprising against Iran's king, who had been accused of committing numerous human rights abuses against Iranian dissidents through his Bureau for Intelligence and Security of the State. The Carter administration's refusal to extradite Pahlavi was cited by the hostage-takers as proof of complicity on the part of the United States, which, in turn, denounced the Iranians' hostage-taking as an egregious violation of the principles of international law, such as the Vienna Convention, under which diplomats and diplomatic compounds are to be granted immunity from coercion and harassment.

A diplomatic courier is an official who secures and transports diplomatic bags. Countries have utilized diplomatic couriers to handle important documents, artifacts and supplies between different countries since the 12th century. Following the 1961 Vienna Convention on Diplomatic Relations, couriers are placed under diplomatic immunity while performing their work. Couriers are usually hired by a specific country and are tasked with protecting and managing bags from being opened. Some couriers are assigned on an ad hoc basis, but in those cases they are released from immunity once their bags have been delivered. The original definition of a diplomatic courier focuses on handling bags, but couriers today also deal with logistical affairs and digital communications.