Why Iran shut the Strait of Hormuz after decades of holding back

US forces have struck hundreds of Iranian targets – including in the southern port city of Bandar Abbas – over three consecutive nights in a bid by the US president, Donald Trump, to regain some modicum of control over the Strait of Hormuz. Trump has also inscribed the US as the “guardian” of the vital waterway, reviving a naval blockade of Iranian ports and demanding a 20% charge on all cargo passing through. His own secretary of state, Marco Rubio, had ruled out such a toll just two weeks…