Inside Iran’s deadly armory and its capabilities to fight the US

In the hours after Iran is said to have downed a $125 million U.S. surveillance drone over international waters with a surface-to-air missile, despite Tehran’s vehement denials, President Trump gave the green light to retaliatory military strikes before later ordering a halt amid the alarming spike in tensions. But just how capable is Iran when it comes to fighting back and what lurks inside their shadowy arms arsenal and how it’s military structured?