U.S. airstrikes on Iranian nuclear facilities are sharpening the focus on one option Iran has yet to really deploy in the conflict: disrupting regional oil trade, especially through the critical Strait of Hormuz.

Iran has over the years threatened multiple times to shut the strait — a narrow stretch of water through which a fifth of the world’s oil supply flows each day. But in practice, Tehran has numerous less drastic options at its disposal to calibrate a response that hurts its enemies while limiting the impact on allies like China, its biggest oil buyer.

A full closure of Hormuz for more than a few hours or days is a nightmare scenario that many observers think improbable. It would choke off flows and spike crude prices — JPMorgan analysts said by almost 70% — fueling global inflation and weighing heavily on growth.