To understand Trump’s abusive relationship with Saudi Arabia, we have to understand Nixon’s affair with Iran

Sensible people learn from relationships like this, and take care not to fall into another one just like it. The US, however, has not been so careful

A controversial president is in the Whitehouse. America’s largest oil supplier is a monarchy, which is also the US’s largest arms customer. And American foreign policy in the Middle East is almost entirely dictated by its one-sided relationship with this oil-rich monarchy.

While this sounds much like a description of America’s slightly unnatural relationship with the Wahhabi Saudi Arabia today, it is also an exact description of the relationship between the US and the Iranian Shah in the 1970s.

And look how well that ended.

It seems like the US has a habit of becoming infatuated with Middle Eastern monarchies and forming unhealthy relationships with them that end in tears, drunken tweeting and foreign policy disaster.

Let’s go back half a century. In the 1960s the British empire was gently disintegrating and London realised it could no longer afford many of the things it used to. These things included battleships, cigars and the ability to keep a permanent military presence in the Persian Gulf.

America was nervous. It had become deeply dependent on oil from the Middle Eastern region to fuel the constant growth on which US hegemony was built. But now that its bankrupt ally could no longer afford to keep the peace (or ensure an ongoing supply of cheap oil), a strategic problem had emerged.

It was then that America met their prince – the handsome, carefully coiffed Mohammad Reza Pahlavi. His family had ruled Iran for 2,500 years. Yes, that’s right: 2,500 years.

The nations’ alliance had got off the ground under president Truman after the Second World War and was based on the principle that the US would guarantee Iran’s security in exchange for oil. The massive growth in the US economy after the war meant that its oil requirements had ballooned, and Iran needed a muscular friend to help it survive in a rough neighbourhood. Initially, arms sales were limited but by the 1960s Iran was the biggest buyer of US military hardware in the world.

The Shah used smooth talk and guile to wrap the US around his finger. America was aware of the deeply undemocratic and brutal nature of his regime, but he wooed them with oil and scared them with pillowtalk about the Soviet and Arab nationalist threat to his rule, and thus to their oil supply. He could do no wrong. The guns kept coming, and with it the implicit promise that the US would defend him from any threat.

But he was going down a dark road. And the US cheerily skipped down that road with him.

Eventually the Shah had managed to make enemies of the Islamic clerical hierarchy, the socialist left and the nationalists. Making enemies of all these groups was quite an achievement and meant that, even with US support, he could no longer survive.

The fall of his unlovely regime may not have been hugely significant but what was significant was the fact that, as his devoted “friend with benefits”, the United States had now inherited all his enemies. Thanks to its blind devotion to their handsome prince, the US had made enemies of almost everyone in the region. By allowing him and his oil to have undue influence, they found themselves in possession of a foreign policy that made no sense to America and did not serve its interests.

The disaster was so enormous that it triggered a hostage crisis, a brutal war between Iran and Iraq, and 40 years of hostility between Iran and America. It was the ugliest breakup imaginable.

Basically the US was like someone who falls into an unhealthy relationship, gets a weird tattoo, ends up compromising far too much, lets their partner make all the decisions, loses every friend they have and then has to pay their ex’s gambling debts when it ends.

Sensible people learn from relationships like this, and take care not to fall into another one just like it. The US, however, has not been so careful.

With the Arab nationalists and the Ayatollah (who, thanks to the public bromance between the Shah and America, now hated the US) controlling much of the Middle East’s oil, America needed a new friend.

A friend with lots of oil, who needed protection. Saudi Arabia was that friend.

Just like it did with the Shah, the US has completely compromised itself for the sake of this relationship. The US has ignored gross human rights abuses, turned its back on moderate Muslim governments and allowed the most extreme wing of Sunni Islam to proliferate. The nation has even ignored the fact that Saudi money seems to have funded the Taliban and 9/11 attacks, which Saudi Arabia has long denied.

And now the US president has officially stated that even if Saudi Arabia’s de facto head of state ordered the murder of a Washington Post journalist (which is vehemently denied by Saudi Arabia), it isn’t really that big a deal.

It is another deeply unhealthy relationship that is sure to end badly.