In the nuanced world of diplomacy even the smallest faux pas can cause an international incident. This sensitivity even extends to the choice artwork for the embassy walls.
On taking up a new post, ambassadors are invited to the vaults of the government's art collection to select suitably diplomatic works.
The collection is holding a rare open day on 17 May. We asked two seasoned diplomats, the former British ambassador to Washington, Sir David Manning and the current American ambassador to London, Robert Tuttle, to show us some of the highlights of the collection.
George Gordon Byron by Thomas Phillips
This painting of Lord Byron in Albanian dress was hung in the British embassy in Athens for many years.
Byron died of a fever in Greece while fighting in the Greek War of Independence and is celebrated there as a national hero.
Sir David Manning feels that classical painting of this kind is what people imagine when they think of the government's art collection, but this has changed. As he puts it:
"The Government Art Collection is much more contemporary, much more interesting and challenging than perhaps the clichéd view that it is a lot of dusty old masters."
The American government does not operate the same system of art acquisition. Ambassador Tuttle expressed his admiration for the "living breathing" British collection which draws on the wealth of talent in the contemporary British art scene.
"[They are] out there at the galleries, at the art universities and at the studios looking at art right now."
Queen Elizabeth II of the United Kingdomby Andy Warhol
British embassy wall space is usually used to highlight the great works of British artists, but an exception was made for this work by Andy Warhol.
Sir David Manning admits that some people were sceptical about a less than grandiose depiction of the British Monarch but most were impressed:
"Here is our own monarch, painted by one of the great American painters....this made an enormous connection, an enormous impact."
The British are not the only ones to bend the rules. The American ambassador in London, Robert Tuttle confessed that a painting by British artist Anish Kapoor graces a wall on the first floor of their London embassy.
Print For A Politician by Grayson Perry
This etching by Grayson Perry has recently been chosen for the office of a British cabinet minister. Its content is deeply political, with each detail representing a different sub-section of British society.
Would it make it onto the embassy walls? Ambassador Tuttle would jump at the chance:
"It shows to the whole world the freedom that our artists have to express themselves."
There is, however, a fine line to judge been challenging embassy visitors tastes and damaging relations. As Sir David Manning puts it:
"We are not in the business, frankly, of trying to offend people."
