It’s been suggested British Royal Marines boarded the vessel at the request of America. And the UK is looking at boosting its military presence in the Gulf after an apparent close encounter with Iran’s Revolutionary Guard just days later.
The US, meantime, is turning the screw further on Iran's already faltering economy, and Britain finds itself in an awkward position. It's working with Europe to try and save the 2015 Iran nuclear deal, which the US has abandoned. But it also needs to maintain close ties with Washington as it seeks to leave the European Union.
The situation with the tanker has infuriated Iran with the foreign minister demanding Britain return the ship or face what he called 'the consequences'.
Presenter: Martine Dennis | Guests: Aniseh Bassiri Tabrizi, research fellow at RUSI, the Royal United Services Institute; Mohammad Marandi, head of American Studies Department at the University of Tehran; Phil Diacon, managing director of Dryad Global, a maritime security risk management company
