Diplomacy: Secret service remains closed

The Foreign and Commonwealth Office may be opening its doors to the public gaze, but there is one arm of Britain's overseas representation which most certainly is not: MI6, or Her Majesty's Secret Intelligence Service (SIS). Britain's overseas intelligence-gatherers, or spies, are not having an open day; nor will tourists be invited into their headquarters to gawp.

In some ways, SIS has less of a problem with external image than the FCO. Its brand-new post-modernist building in Vauxhall Cross in south London expresses its soul with peculiar accuracy: mysterious, multifaceted and muted, with a discreet cluster of aerials and dishes tucked away on the roof. Its public persona is set for it by James Bond of the films, dashing, romantic and cheeky.

The reality is probably a little closer to the James Bond of Ian Fleming's books: upper class, with a drink problem and a fragmented personal life. John Le Carre's books show a similar, and less warm - if just as romantic - picture.

SIS has made a number of attempts to modernise for the post-Cold War era. Newer recruits come from many social backgrounds and women are increasingly represented. Its tasks have been extended to include "drugs and thugs" - counter-narcotics work and a focus on criminals. It is also said to be working harder at fighting the proliferation of weapons of mass destruction, and developing its economic espionage.

But then nobody really knows, because it does not have any responsibility to explain itself. It gives regular lunches for media editors, and that is about it.

This air of mystery is something that SIS cultivates, and regards almost as a weapon in itself. It is still highly regarded around the world, and in both the Balkans and the Caucasus, for instance, people ascribe to it far more influence than it possesses. But then perhaps that is the point: the image is more important than the reality.