Iraq, and the entire Gulf region is nervously contemplating the risk of possible Iranian action to close the Strait of Hormuz in response to sanctions imposed by the US and EU.
And that nervousness is echoed around the world, as something of the order of a quarter of the world's oil supply is shipped through the Gulf.
While alternative routes could be found for, perhaps, a quarter of that volume, this would take much longer to get to market and it would increase the cost considerably.
But it is debatable whether it would even be possible for Iran to close the Strait in the face of Western military power. Because the transport route is so vital to the world economy, the US has deployed three aircraft carriers to the area, and both France and UK have also sent vessels.
Iran itself has also indicated that it does not plan to disrupt shipping traffic. Tehran’s Ambassador to France said last weekend, “we don’t have the intention to close the Strait of Hormuz ... Our interest demands the free circulation of vessels in the Strait.”
That policy may change, but there is a determination to among Western powers to maintain oil supply.