Tillerson Warns Against Doing Business With Iran’s Revolutionary Guards Secretary of State Rex Tillerson warned global companies that they do business with Iran’s Revolutionary Guards “at their own risk,” remarks that will add to investment uncertainty in a country eager to reap the economic benefits of a 2015 nuclear accord. Rex Tillerson Photographer: Alex Brandon/AFP via Getty Images Tillerson, visiting Saudi Arabia to help inaugurate an alliance against Iran between the kingdom and Iraq, called on governments to join a U.S. sanctions regime against the Islamic Revolutionary Guard Corps, a hard-line military and political force. “Both of our countries believe that those who conduct business with the Iranian Revolutionary Guard, any of their entities -- European companies or other companies around the globe – really do so at great risk,” Tillerson said at a briefing with Saudi Foreign Minister Adel al-Jubeir. The Revolutionary Guards “foment instability in t...