Alarm bells still ringing over US-Iran tensions

First, the United States withdrew from the nuclear deal global powers brokered with Iran, reinstating sanctions based on unsubstantiated allegations of Iranian violations.

Then came threats from Teheran to scrap the deal and resume nuclear activities.

Then the White House labeled the Islamic Revolutionary Guard Corps a "foreign terrorist organization", prompting Teheran to designate US troops across the region as "terrorists".