In diplomatic practice, expulsion most commonly refers to the host state declaring a member of a foreign mission persona non grata (PNG) under Article 9 of the Vienna Convention on Diplomatic Relations (1961), which allows the receiving state to require the sending state to recall the individual without having to give reasons. If the sending state refuses or delays, the host may simply cease to recognize the person as a member of the mission.
Expulsions are a calibrated tool of statecraft. They are used to signal displeasure short of severing relations, to retaliate for espionage, to respond to human rights abuses, or to coordinate with allies in collective diplomatic pressure. The number of officials expelled, their rank, and the deadline (commonly 24, 48, or 72 hours) all communicate the severity of the message. Tit-for-tat reciprocal expulsions are the norm.
Expulsion can also refer to:
- Expulsion of foreign nationals (non-diplomats), governed by domestic immigration law and, for refugees, constrained by the non-refoulement principle in Article 33 of the 1951 Refugee Convention.
- Expulsion from international organizations, such as suspension or removal of member states. The UN Charter (Article 6) permits expulsion of a member by the General Assembly on Security Council recommendation, though no state has ever been formally expelled from the UN.
- Mass expulsions, which are prohibited under Protocol 4, Article 4 of the European Convention on Human Rights, and under Article 22(9) of the American Convention on Human Rights.
For diplomats, expulsion does not normally constitute a breach of immunity, since the host state is exercising a right expressly preserved by treaty. The expelled official retains immunity for acts performed in their official capacity even after departure.
Example
Following the poisoning of Sergei Skripal, the United Kingdom expelled 23 Russian diplomats in March 2018, prompting a coordinated wave of expulsions by more than 25 allied states.