For visiting heads of state, it must be one of those nagging questions – just how important are they to their British hosts?
The answer, it seems, may well lie not in the size of the honour guard, nor the depth of pile on the red carpet, but in the wine list.
An unusual insight into how the British government entertains its high-end guests has been revealed by the release of the tasting notes for the £3.2m official wine cellar used to lubricate the wheels of international diplomacy at state banquets and Whitehall receptions.