Former Diplomatic Editor of The Times Michael Binyon looks back throughout history at various diplomatic expulsions across the globe

The recent expulsion of 23 Russian diplomats from London and the subsequent reciprocal expulsion of British diplomats from Moscow is a visible indication of a break-down in relations and the present anger at the behaviour of each other’s governments. But it also follows a clear and recognised pattern of behaviour, designed to regulate the way nations treat each other’s envoys and prevent quarrels escalating quickly into armed conflict.

In normal times, diplomats serve in embassies overseas after they have been accredited by the host country. In other words, they have been checked out by the receiving government and allowed to take up residence, with the promised protection of immunity from arrest or prosecution. Sometimes, however, they are refused agrément– which means that they are not acceptable for some political reason and will therefore not be allowed to take up the post for which they have been nominated by their government.

But if a diplomat already in post is found, for whatever reason, to have violated the norms of political behaviour or has behaved badly or has committed a crime, they can be declared persona non grata(an unacceptable person). That means that their diplomatic immunity is rescinded, and unless they leave the country within a given period they will be arrested.

All these formal steps are laid down in the Vienna Convention of 1961, the code drawn up to govern the way countries treat each other’s diplomats and signed by 191 countries – virtually the entire world. This was aimed at stopping the arbitrary arrest of diplomats or their exploitation as hostages, as often used to happen even in the nineteenth century. Article 9 of the convention says that a state may ‘at any time’ declare a diplomat persona non grata, ‘without having to explain its decision.’ So Britain, angered by the presumed involvement of the Russian government in the poisoning of Sergei Skripal, the former Russian spy, and his daughter Yulia, did not formally explain why each of the 23 diplomats was ordered to leave – while nevertheless letting it be known that Britain was targeting what it presumed were Russian intelligence agents. Similarly, the Russian tit-for-tat action taken only a few days later did not formally link the expulsion of British diplomats to the Skripal affair, but Moscow made it quite clear that this was a retaliatory move.

Expelling diplomats en masse became a characteristic of the Cold War, when diplomats from the Soviet Union and its allies were often suspected of being intelligence agents and were ordered to leave – usually after a spy scandal. Inevitably, the Russians and their allies retaliated, kicking out western diplomats. The largest single expulsion was in 1971, when Britain’s Conservative government expelled 90 of the Soviet Union’s 550-stong embassy in London and stopped a further 15 diplomats from returning. The move, prompted by the defection of a senior KGB officer, dealt a lasting blow to the KGB in London. The Soviet retaliation was relatively restrained – with only 18 Britons expelled from Moscow.

There were further mutual expulsions over the years, usually after revelations of spying. In each case, however, the two sides followed the rules and conventions. Diplomats were given up to a week to leave, and were neither harassed nor arrested before their departure. In 1971, journalists went to the airport to witness the departing Russians leave – and several journalists from The Timesrecognised many of the Soviet side with whom they had played a football match only a week earlier.

There are other ways, however, of showing diplomatic anger. One of the most common is the withdrawal of an ambassador ‘for consultations.’ This is a signal that stops short of a formal break in diplomatic relations but makes clear that a government finds the behaviour of another government unacceptable. It is not an unusual move, and even occurs between governments that are formal allies. When, for example, the Turkish government accused the Dutch and German governments of behaving like the Nazis because they refused to allow Turkish politicians to campaign in Germanyor the Netherlandsbefore the 2017 referendum, the Netherlands responded earlier this year, after months of wrangling, by withdrawing its ambassador from Ankara and preventing a new Turkish ambassador from taking up his post. It was a clear signal that relations between these two Nato members had reached a serious crisis point, even though the Netherlands is the biggest overseas investor in Turkey’s economy.

The final signal of diplomatic anger is the formal break in diplomatic relations, the withdrawal of all diplomats and the closure of an embassy. This often happens either when war breaks out, when rioting mobs target an embassy or when there is a sudden and furious political row. Britain and Iranhave several times broken off diplomatic relations since the overthrow of the Shah in 1979. America broke relations with Cubashortly after President Castro seized power and did not restore them until half a century later. Egyptbroke relations with the USon the outbreak of the Six Day War in 1967 and did not restore them until Henry Kissinger arrived in Cairo in the aftermath of the 1973 Arab-Israeli war.

The closure of an embassy is expensive, dangerous and means an end to almost all diplomatic exchanges. It happens after war breaks out: Soviet and German diplomats were allowed to leave each other’s capitals after Hitler’s invasion of the Soviet Union in 1941, although many thought they would simply be seized and held prisoner. Britain closed its Embassy in Kabul in 1989 after the fall of the communist government and the outbreak of civil war, and did not reopen the mission until after the defeat of the Taliban in 2001. Syriahas currently withdrawn all its diplomats from London, although the Embassy is nominally still open, manned by locally employed staff.

When diplomatic relations are broken, each country seeks to be represented by another friendly power and is sometimes allowed to send its diplomats back to work under the other country’s flag.  Often it is the Swiss, traditionally seen as neutral, who undertake the task. Britain was represented by Switzerland’s mission in Iran for some years. The American ‘interests section’ in the Swiss Embassy in Havana was for years a large fully-manned US embassy in all but name. The Cubans used the Czechoslovak Embassy in Washington.

Sometimes, as is the case in the current diplomatic row between Britain and Russia, the ambassador himself is not expelled. Normally he would be seen as the prime target for diplomatic anger. But countries that need to continue doing business with each other, such as Britain and Russia, recognise that the presence of an experienced ambassador is the best way of getting forceful messages back to each other’s capitals. Alexander Yakovenko, the respected and long-serving Russian ambassador, has remained in London and has been active in publicising his country’s views and Moscow’s anger over Britain’s actions.

Nevertheless, it takes some time before countries get over a diplomatic sulk. And when ambassadors are returned or diplomats again accredited, it is usually done quietly and without fanfare. It remains to be seen how long it will take before Moscow is able to replace all the diplomats expelled from Britain and more than 20 other western countries.