The US blockade on the Strait of Hormuz could carry massive implications – as it seeks to prevent ships from entering or exiting all of Iran’s ports. Following failed peace talks in Islamabad on April 11th, President Trump vowed to carry on the blockade as a means to strangle Iran’s already weakened economy. But who does the blockade target? How will the US actually enforce it? And what are the potential impacts? Here’s what to know.