Iran’s foreign minister, Mohammad Javad Zarif, also poured derision on the Republican letter in a statement expressing astonishment that members of Congress would seek to undermine a US administration by writing directly to a foreign power, and suggesting that the letter’s authors had much to learn about international and even US law… Zarif, like President Hassan Rouhani and several other senior members of the Iranian government, holds an advanced degree from a western university, and appears to have taken umbrage at the condescending tone of the senators’ letter. He delivered his own lecture in response.

‘I wish to enlighten the authors that if the next administration revokes any agreement with the stroke of a pen, as they boast, it will have simply committed a blatant violation of international law,’ he wrote.