Strait of Hormuz could be vulnerable to Iran retaliation. Here's what to know about the vital oil trade route.

The United States launched military strikes on three Iranian nuclear facilities Sunday morning local time, an action President Trump said aimed to neutralize a threat "posed by the world's number one state sponsor of terror." It was widely seen as a turning point in America's involvement in the ongoing Middle East conflicts as the first direct intervention by U.S. forces in the war between Israel and Iran. 

The strikes have ignited concerns about possible Iranian retaliation and what form such responses could take. Among them are fears Iran could block oil exports through the Strait of Hormuz, a major commercial trade passage that the country partly controls.