Former Diplomatic Editor of The Times Michael Binyon tackles the greatest nightmare a diplomat can face: organising a state visit 

A state visit is the acme of diplomatic relations, the symbolic celebration of friendship between two nations and the occasion to look back on past ties and lay the foundations for even deeper mutual links.

A state visit is almost the greatest nightmare diplomats have to face. It has to run faultlessly. If the slightest thing goes wrong – a flag missing, a delay in the schedule, a comical incident or a lapse in security – there is hell to pay. The gaffe will be splashed across the world’s press and all the anticipated goodwill thrown away.

Little wonder, therefore, that months and even years go into the planning of state visits. Every minute of the day has to be choreographed, every step of the visitor’s route measured out and timed, every nuance and joke in the set speeches weighed for effect. What will the visiting king or president eat? What will they wear? What language will they speak at the formal dinners? What would be an appropriate gift? What will the spouse like to be seen doing during her special separate programme? And how can the visit be co-ordinated with the timetable of Buckingham Palace, which is usually fixed at least two years in advance?

For every visit involving The Queen or other members of the royal family, add an extra year needed for preparation. There is the protocol, the etiquette and the ceremony to consider. The speeches must be as stately as they are vacuous, but they have also to be seen by the hosts to be flattering while giving the state visitor an opportunity to bolster the image of his country.

The symbolism of every engagement during the visit – generally lasting two or three days – must be visible. The press must be persuaded to give the occasion generous, and, if possible, positive coverage. The visitor’s wishes must be accommodated and the foibles of a headstrong or unpredictable figure – an impromptu plunge into the crowd, a sudden political rant, an attempt to nick a few souvenirs from the Palace – must be anticipated and tactfully thwarted.

Of course not all visits are on the level of a state occasion. Most, in fact, are usually working visits, when a prime minister or president drops in for a day, or at most two, to spend time talking, discussing and sometimes arguing about mutual relations and the burning issues of the day. These visits are long on politics and short on ceremony, and do not usually involve banquets or appearances with The Queen.

Sometimes, however, a working visit – especially one seen as politically important – can be raised almost to the level of a full state visit, with ceremony, a formal address to Parliament, a guard of honour and all the traditional trappings intended to make the visitor feel particularly honoured and welcome.

The recent visit of Angela Merkel, the German Chancellor, was one such occasion. She spent less than 12 hours in all in Britain, but it took months of behind-the-scenes preparation by British and German diplomats. She gave a speech to a joint sitting of Parliament – and so the first issue was to ensure that enough MPs were present and not on some trip to Africa or opening a fete in their constituency. She also took tea with the Queen, so a slot had to be found in the royal timetable to ensure that Europe’s most famous head of state had time to greet Europe’s most powerful head of government.

An enhanced working visit is especially tricky. The main issue is finding the right tone. What impression was the Merkel visit meant to convey? Was it to be soaring ceremony, with guards of honour, carriages and trumpeters, or an informal fireside chat between Ange and Dave in his flat over the shop?

“There is an idea nowadays that informality creates intimacy,” said Sir Christopher Meyer, a former British Ambassador to Washington. This can cause confusion. He remembers Helmut Kohl saying how he dreaded visiting Downing Street ever since his first encounter with Mrs Thatcher there. She had invited him to tea, and was bustling about with the teapot and the plates of cakes. “I was just starting to relax,” the former German Chancellor recalled, “when she span round and fixed me with a stare: ‘Now, Helmut, what about the Common Agricultural Policy?’”

The other big question is which guests to invite. It went disastrously wrong some years ago for Thatcher. She gave a lunch in Bonn for prominent Britons living in Germany. In her speech, she picked out by name a well-known scientist. There was silence. Heads turned. He appeared not to be present. She laughed, embarrassed, and then singled out a musician. He, too, was absent. She moved on to a third person who was also not there. Her face was thunderous and her anger reverberated around the Bonn embassy for days. Someone, it turned out, had given Downing Street the list of those invited, not the list of those who had accepted.

On the whole, ambassadors agree, the Foreign Office machine is practised and efficient. The Government Hospitality Department knows which dishes and wines to serve, the police do security checks and the security services liaise with the visitor’s bodyguards.

Everyone remembers the nightmares, however: President Ceausescu of Romania, who strained even The Queen’s legendary patience, and whose entourage stole what they could; President Mobutu of Zaire, who insisted his staff carry their guns; and Andrei Gromyko, the grim-faced veteran Soviet Foreign Minister, who thought that the antique barometer offered to him as a present was a balalaika and tried to play it.

A US presidential visit is probably the most taxing. When George W Bush came to London in 2003, at the height of public anger over the Iraq war, the US Secret Service descended in their scores on London, and demanded that the city should be virtually locked down. They also insisted that the presidential helicopter should be allowed to land in Hyde Park – a demand that caused a strong public reaction. It was eventually allowed to land in the gardens of Buckingham Palace, but the temporary helipad churned up the manicured lawns and the helicopter rotors caused considerable damage to trees and shrubs that had been there since Queen Victoria’s time. The Queen, apparently, was not amused.

Some things on visits, state or working, cannot be controlled – especially the press. Diplomats just have to hope their bosses say the right things. Often they don’t. President Assad of Syria went right off message after his meeting with Tony Blair, and the British Prime Minister looked distinctly uncomfortable at their joint press briefing when the visit concluded. Angela Merkel, however, is famously cautious. She got it just right, telling MPs and those hoping for miracles from her visit that they would be disappointed, while insisting she was committed to keeping Britain within the European Union. Diplomats were able to breathe easy. But they then had the trickier task sorting out the big question: what did she actually promise