How risky would it be to escort ships through the Strait of Hormuz?

President Trump's call for US allies to help escort oil tankers through the Strait of Hormuz has been met with a muted response so far. None of the countries he's called on, including the UK, France and China, have said they will take part for now.

Military and naval experts say escorting vessels through the narrow waterway next to Iran faces a number of formidable challenges. BBC Verify's Ben Chu explains why.