Now, quite how the idea for Ambassadors (BBC Two, Wednesday) came about is anybody’s guess. A comedy drama about the inner workings of the British embassy in a fictional Central Asian republic called Tazbekistan? What? But it is certain that the extensive research carried out by the writing team of Rupert Walters and James Wood (who have written for Spooks and Rev respectively) added a vital dose of realism, without which it would just have been silly.