Reuters reports that:
Iranian naval vessels fired shots at a Singapore-flagged tanker in the Gulf on Thursday, in what appeared to be Iran's latest attempt to settle a legal dispute by force with passing commercial vessels, U.S. officials said.
This may be merely an opening salvo as:
Shipping industry officials said they were bracing for the likelihood of even more tensions at sea, which could lead to a spike in shipping costs. "The pattern looks like the Revolutionary Guards are using a commercial pretext to intervene in the incidents to date," said one shipping underwriter. "This could start to impact upon (insurance) rates.”
Which might be the least of the problems. As:
The episode in the Gulf coincided with mounting concern over an Iranian cargo ship headed to Yemen. A Saudi Arabia-led coalition has imposed an air and maritime blockade to stop weapons supplies reaching the Iran-allied Houthi rebels.
And “Brigadier General Massoud Jazayeri, Deputy Chief of Iran's Armed Forces, warned of war if the ship, which Tehran says is carrying humanitarian supplies, was attacked.”