In his speech at the Conservative Party conference, Boris Johnson talked at length about the influence of "Global Britain". But where is this influence when it comes to Nazanin Zaghari-Ratcliffe? For once the foreign secretary should stop grandstanding and knuckle down to the real work of securing my constituent's freedom from an Iranian prison cell. Getting one young Hampstead mother out of jail might not be the kind of glorious, earth-shattering diplomatic triumph that Mr Johnson dreams of. But it would mean a huge amount to the people caught up in this nightmare.