In detaining local employees of the British embassy in Tehran, the Iranian authorities appear to have mined a deep vein of hostility toward Britain which has lasted, off and on, since the latter's imperialist grandeur in the 19th century. And it isn't hard to enumerate the many flashpoints in the turbulent relationship between Iran and the "little Satan" in more recent times.
They include Tehran's identification of Britain with US support for Iraq during its war with Iran in the Eighties, the break in diplomatic relations in 1989 over Ayatollah Khomeini's fatwah against Salman Rushdie, the five-year sentence of Briton Roger Cooper on spying charges which he persuasively denies; and two years ago, the stand-off triggered by Iran's seizure of 15 British sailors for an alleged foray into Iranian waters.
Looming, too, behind these later tensions was the 1953 coup which ousted Mohammed Mossadeq, the popular and elected Persian prime minister. Barack Obama sees this as a sufficiently important event in the history of relations between Tehran and the West to have issued the first presidential disavowal of the US's part in the coup in his Cairo speech this month. What he did not mention was British intelligence's active assistance to the US at the time, or that the trigger was Mossadeq's determination to nationalise Anglo-Iranian oil, the predecessor of BP.
Yet history cannot alone explain the extent to which the regime has singled out Britain in the past few days. Some British policymakers will see it as ironic, given that while the UK has been a strong opponent of Iran's perceived ambitions to be a nuclear military power – not to mention Mahmoud Ahmadinejad's ugly Holocaust denials and anti-Israel rhetoric – she was a key part of the European effort during the Bush era to seek a diplomatic rather than military solution to the mounting crisis.
There are several current grievances. One is the new BBC Persian TV channel, which despite or rather perhaps because of, its determination to maintain journalistic objectivity, has angered hardliners in the Iranian authorities. Another, mentioned by the Middle East analyst Rosemary Hollis to the BBC, may be the presence in Britain of the Iranian opposition group MKO, which was removed by the EU from its list of terrorist groups earlier this year.
The most optimistic interpretation of Tehran's heavy-handed conduct against Britain is that it could be a way of maintaining an anti-Western stance without destroying the chances of the negotiations with the US which Mr Obama has been seeking. If Britain were to become a lightning conductor, paradoxically keeping alive the chances of the diplomatic solution to Iran's nuclear stand-off which Mr Obama has made clear he wants, then the short-term pain could be a price well worth paying. But for now, and in the present worryingly volatile context, that is a far from bankable prospect.