Swimming in Iran

Foreign correspondents. Nick Thorpe on the Russian speakers in Ukraine who want the future of their country linked to western Europe, not to Moscow; Thomas Fessy examines how the Islamist fighters of Boko Haram are extending their operations out of Nigeria into neighbouring Cameroon; Shaimaa Khalil in Karachi on the difficulties and the dangers health workers face trying to convince people to be immunised against polio; Chris Bockman in Montpellier has been learning what an exiled Syrian billionaire has to do with the local rugby club and what's the correct etiquette for an American woman keen for a swim in Iran? Amy Guttman has been finding out.