WATCH: A Brief History of US - Iran Relations

The United States and Iran have been at odds ever since a CIA-backed coup reshaped Iranian politics more than half a century ago. Brutal secret police, the infamous hostage crises and the fatal downing of an Iranian civilian airliner are just a few of the seminal events to chill relations in the decades since.

But the ice between the two nations may be thawing as the deadline for a historic nuclear deal approaches this week. Watch the video above to experience the gripping events both sides must overcome to get there, in ABC News' "A Brief History of U.S.-Iran Relations," narrated by George Stephanopoulos.