I'm ABC global affairs editor Laura Tingle in Dubai. This is the last of my daily updates; ABC correspondent Matt Doran will take over from Monday.
Iran has increasingly been turning the war with the United States and Israel into an economic war based on oil. You will have seen the pictures on the news of burning oil refineries and oil tankers across the Gulf.
Scores of tankers are sitting on either side of the Strait of Hormuz unable to move, and vulnerable to Iranian attack. Unable to move, that is, unless they are carrying Iranian oil.
Iran’s Supreme Leader said on Thursday the Strait would remain closed, and a defence spokesman said no oil would pass through that could assist the United States or Israel.
Having provoked this situation, the United States has so far declined to help, with the US military reported to have turned down a series of requests from around the region to escort oil tankers or other civilian ships through the Strait. Donald Trump has suggested that the US and its allies could provide military escorts to ships crossing the waterway “when the time comes”.
Is there any other way of getting the 20 million barrels of oil a day that usually flows out of the Gulf to global customers? Well yes, there is one way to get at least some oil out.
In the 1980s, Saudi Arabia built a 1200km-long pipeline — the East West Pipeline — across the width of the Arabian Peninsula to carry oil which would normally be exported via the Gulf to the Red Sea.
The Financial Times reports that "about 30 so-called very large crude carriers, each capable of carrying more than 2 million barrels of oil, are heading to the kingdom’s western port of Yanbu over the coming days, according to shipbrokers, compared with a long-term average of about two a month".
But the new route carries its own dangers, the FT notes. "To enter the Red Sea from the south, the tankers will need to brave the Bab al-Mandab strait, where ships have been struck in recent years by Yemen’s Houthi militants — and which is also within range of some Iranian missiles."
Thanks for joining me. You can keep track of the latest updates from Iran and around the world throughout the day via our live blog.