The dispute over Iran's nuclear program has again rocked oil markets. And Iran is threatening to close the Strait of Hormuz, which is just 34 miles wide yet serves as the passageway for 20 percent of the world's oil.
This is not a new drama. In fact, it was a recurring issue in the 1980s. Still, there's been relatively little activity among Gulf oil producers to find alternative routes to get their oil to market.