The Vienna Convention on Diplomatic Relations lasted because it invented very little. Eighty-one states met in Vienna from 2 March to 14 April 1961, and the treaty was signed on 18 April. Most of what they signed had already been diplomatic practice for more than 200 years, which the UN’s own history of the treaty gives as the first reason it worked.
The second reason is reciprocity. Every state is both a host and a guest, so a country that mistreats foreign envoys can expect the same for its own. The UN account names that as the sanction that keeps states in line.
Where the rules came from
Safe passage for an envoy is one of the oldest rules between peoples. Ancient Greek cities and the states of ancient India both treated the person of an emissary as untouchable. By the Congress of Westphalia in 1648, permanent embassies had become the normal way for rulers to do business, and rules grew up over the next century on immunity, embassy premises and tax.
Writers such as Grotius in 1625 and Vattel in 1758 described those customs. Nobody wrote them into a treaty for a long time. The Congress of Vienna in 1815 settled one bitter question: ambassadors would rank by their date of arrival at post. A Pan-American convention signed in Havana in 1928 tried to codify immunity, but the UN history says it did not reflect real practice well.
How the UN turned custom into a treaty
Yugoslavia asked in 1952 for the subject to be given priority. The General Assembly passed it to the International Law Commission, which appointed Sandström of Sweden to draft the articles. Twenty-one governments sent comments on the 1957 draft, and a revised version in 1958 became the basis for the Vienna conference.
The result runs to 53 articles in dry technical language. It covers how missions are set up, the diplomatic bag, the protection of embassies and whether diplomats pay tax. Writing in The Guardian on its 50th anniversary, the author counted 187 states as parties.
The clause that still causes trouble
Article 29 says the person of a diplomatic agent is inviolable and may not be arrested or detained. The BBC put the number of people covered by diplomatic immunity in the UK at about 25,000, families included.
The best-known British case is PC Yvonne Fletcher, shot dead outside the Libyan Embassy in London in 1984. The people responsible had immunity and were expelled rather than tried. In 2010 the then Foreign Secretary, William Hague, published details of 18 crimes diplomats in the UK had been accused of that year. Embassies have also run up £95m in unpaid London congestion charges, arguing the charge is a tax and so exempt under the convention.
The treaty does impose duties. Diplomats must respect the host country’s laws and stay out of its internal affairs, and the bag may carry only items for official use. The receiving state’s main remedy is to expel the diplomat, which the Guardian piece called a sanction that has lost its sting.
Immunity also has limits a court can test. Facing a claim from his ex-wife in London, Saudi businessman Walid Juffali claimed immunity as Saint Lucia’s representative to the International Maritime Organisation. The Court of Appeal held that as a permanent UK resident he was immune only for official acts.
The human rights barrister Geoffrey Robertson told the BBC the convention made sense during the Cold War, when staff in hostile countries risked being framed. Whether a rule built for that world should still shield a drink-driver is the question the treaty’s critics keep asking.
