America's naval blockade of Iran is meant to choke Tehran into lifting its own restrictions on the Strait of Hormuz, but will it work and can it be enforced? Former Royal Navy Commander Tom Sharpe joins Roland Oliphant to explain the operational challenges. The first day of the maritime siege has drawn vocal condemnation from Beijing, in the latest sign of growing Chinese involvement in the crisis. Chinese officials were key to persuading Iran to accept the ceasefire. There are claims that