Around 20% of the world's oil passes through the Strait of Hormuz, off the coast of Iran. Oil prices are higher today because of how a potential U.S. intervention could limit oil supply.
The European Union has threatened to embargo oil from Iran. Iran snapped back, saying if that happens, it won't let any oil ships pass through the Strait of Hormuz. How might this affect Europe and the U.S.?
Iran has threatened to block the strait if President Obama signs a bill to impose sanctions to keep it from making nuclear weapons. The impact on oil prices worldwide would be major and immediate.