On very, rare occasions, diplomats on foreign postings choose to defect.
Envoys can also, every now and then, be recalled home if they fall out of favour with their government or make a mistake.
But Lord Ricketts, a former permanent secretary at the Foreign Office, said that he cannot recall a situation in the UK – before the standoff at the Myanmar mission – where a serving ambassador has been locked out of his own embassy by his own staff and is refusing to stand down.
“This is unprecedented in my experience,” Lord Ricketts said, when asked about Kyaw Zwar Minn.
The ambassador made himself unpopular with the military junta that seized power in Myanmar earlier this year when he spoke out against the coup a few weeks ago, voicing support for deposed leader Aung San Suu Kyi.
He said what happened on Wednesday – when his deputy and defence attache apparently took charge of the mission and he was forced to sleep in his car – was in response to these comments.
Yet, when asked by Sky News on Thursday what he wanted to happen, the diplomat, himself a former military colonel, said that he wanted the Foreign, Commonwealth and Development Office to kick these people out so he could return to his post.
“I am the ambassador,” he said.
It creates a difficult, diplomatic dilemma for the UK.
Dominic Raab, the foreign secretary, has strongly condemned the coup in Myanmar and called for a return of diplomatic rule.
He has also criticised the military regime for its “bullying activities” in London and praised the ambassador for his courage.
However, diplomatic protocols mean that the UK government has to deal with the governments of other states, even when it does not like them.
Foreign states “have to have ambassadors in London representing their governments”, Lord Ricketts explained.
“If this poor gentleman is no longer representing the Myanmar government then effectively he becomes a dissident and he might have to apply for asylum if he wants to stay in this country,” he said.
When asked whether he would make such a move, the ambassador told journalists he had not yet decided.
But he clearly understands that a return to Myanmar – where hundreds of anti-government protesters have been killed – would be hugely dangerous.
Asked by Sky News whether he would return home if the UK did not back his attempt to remain as ambassador, he said: “You want me to get killed?”