Rob Macaire joined the Ministry of Defence in 1987, and worked on a number of issues including procurement policy and supporting Special Forces, before transferring to the Foreign and Commonwealth Office (FCO) in 1990.

He served as Political Counsellor in New Delhi, India from 2004 to 2006, during which time he led a team responding to the 2004 Indian Ocean earthquake and tsunami in Phuket, Thailand.

In Nairobi, he was involved among other things with Kenyans' efforts to fight corruption in their country,[5][6][7] support for Kenya's new constitution in 2010,[8] and was responsible for UK dealings with Somalia, including kidnap and hijack cases.

[11][12] In reaction, the FCO described his arrest as "a flagrant violation of international law", and Foreign Secretary Dominic Raab suggested that Iran was engaged in a "march to pariah status".

[14] Iranian judges called on the government to expel Macaire by declaring him persona non grata as placards and cutouts of him were burnt, and protesters chanting 'Death to the UK' outside the British Embassy in the capital Tehran.