If recent history is any indication, America’s killing of the head of Iran’s military, Qassem Suleimani, will drive already strong tanker rates even higher. Fallout could be “like putting a blowtorch to a pile of oily rags,” said Evercore ISI analyst Jon Chappell.

Spot rates for very large crude carriers (VLCCs; tankers that carry 2 million barrels of crude oil) currently average $96,600 per day, more than double the rates of a year ago.

When Middle East incidents occurred in 2019, they came at times when oil-trade volumes were…