Iran crisis: What's really happening on the ground?

U.S. President Donald Trump has urged Iranian demonstrators to keep protesting, promising that "help is on the way," while warning that any country doing business with Iran will face a 25 percent tariff on trade with the United States. Tehran, however, says the situation is under control. Iranian officials insist that communication channels with Washington remain open, while the country prepares for either dialogue or war. So what's really happening on the ground in Iran? What are the root causes of the protests? And how do ordinary Iranians view the U.S. offer of "help"?