The war between Israel and Iran has raised concerns that Iran could try to close the Strait of Hormuz, the world’s most important oil chokepoint.

Iran has threatened to close the Strait of Hormuz, in what would serve as another act of retaliation after the U.S. launched strikes on three key Iranian nuclear facilities over the weekend.

Iran threatened to close the Strait of Hormuz, a vital shipping lane handling 20% of global petroleum demand, in response to U.S. and Israeli strikes on Iranian nuclear facilities.