Iran's Revolutionary Guard Corps has declared the Strait of Hormuz — a waterway through which around 20% of the world's crude oil supply flowed until the war — closed to any ships  not explicitly granted permission by Tehran, warning of a severe response for any violators.  The global price of crude oil jumped over $110 a barrel on the news Friday. Before the U.S. and Israel launched the war on Iran one month ago, a barrel of benchmark Brent crude was trading at just over $70 a barrel.  The