Yes, there has been some warming, but only from the deep-freeze to almost normal diplomatic relations. The Saudis are still extremely suspicious of Iran, particularly given Iran’s attempts to create difficulties within the country’s Shi’a population.

I don’t think a US presence is a total deterrent. The US could make it expensive for Iran to create a war, but couldn’t necessarily stop it. Saudi oil facilities are a 5-minute flight from Iranian air fields; even shorter for missiles. Closing the Straits of Hormuz can be accomplished within minutes as well. Iran has shown itself willing to pay high prices in upholding its policy decisions. Even were it to be severely punished afterwards, the damage it’s capable of inflicting would gravely affect the world economy.

Saudi Arabia, according to the book, has some alternatives, but not enough to nearly make up for lost traffic through the Gulf. Pipelines to the west could carry, conceivably, about half of what moves through the Gulf. That diversion would also add at least five days to shipments to Asia, where most of the Gulf’s oil is currently going.

Would you comment a bit on Saudi-Iran relations? I understand the bit on Iran’s ability to quickly close off oil traffic from the Gulf, but I have a few questions about this.
First, isn’t there an alternative pipeline with capacity to carry oil to the ports on the West coast in Saudi?

Second, isn’t the US presence in Iraq (along with other locations in the West Asia area) sufficient to deter such a threat from Iran against Saudi?

Third, hasn’t there been some rather warming of relations between Saudi and Iran in the past 10 yrs? I remember Cordesman addressing this, but do not remember it being an extensive discussion. I’ve not come across any treatment of this particular topic beyond Cordesman and would appreciate your input. Many thanks!