Blockade by Permission: How Iran Determines Who Gets Through Hormuz

For roughly two weeks, the Karachi, a Pakistani-flagged Aframax tanker loaded with crude at Das Island in Abu Dhabi, sat waiting for a signal that never came through official channels. When it finally moved, it did not take the standard shipping lane. It hugged the Iranian coast, threading through the narrow gap between the islands of Larak and Qeshm, a route mariners are normally advised against,