Of all the present foes of America it is Iran which has consistently been over time the number one.  Since its Islamic Revolution in 1979 that overthrew the secular-minded Shah and supplanted him with a militant, sometimes warlike, Islamic theocracy, it has been America’s Great Satan. (But for Europe rather less so, although no country has broken ranks with Washington.)

In the current edition of Foreign Affairs two professors, Daniel Benjamin and Steven Simon, write, “Imagine historians 100 years from now trying to decide which foreign power the US feared most in the decades from the late Cold War…They would see Russia first as an archenemy, then as a friend, and finally as a challenging nuisance.

They would see China become a great power rival. North Korea would appear as sideshow. Only one country would be depicted as a persistent and implacable foe: Iran.”

A couple of months ago it looked as if President Donald Trump would give the order to attack Iran but then pulled back, comfortable that the West’s sanctions were ruining the Iranian economy.

As in its early years the regime has been profoundly irritating the US. It has returned to enriching uranium towards a level that could mean, if it wanted to, it could one day build a nuclear bomb.

It has been supporting Bashar al-Assad in Syria and provoking Israel via its surrogate, Hezbollah, in Lebanon and giving help to the rebelling Shi’ites in Iraq.

In Yemen it has given modest support to the Houthi uprising. Only in Afghanistan where its interests coincide has Iran unofficially worked on the same side as the US and Nato.

One fifth of the world’s exported oil flows through the Persian Gulf on which Iran has a long shoreline. None of the oil goes to the US but interruption can affect the price of oil. Ironically, much of it goes to China, a supporter of Iran.

Contrary to panicky voices in Washington the Straits of Hormuz at the Gulf’s head cannot be closed. It’s too wide for that. Nevertheless, the Iranians have shown with their recent sabotaging of two big (non American) oil tankers that they can pinch the West’s nerves.

In balance of power terms Washington’s obsession with Iran is absurd. Its economy is barely 2% as large. The US and its allies in the Middle East- Israel, Saudi Arabia and the United Arab Emirates- together spend 750 billion US dollars annually on their armed forces. That’s about 50 times more than Iran.

It has missiles but as yet they don’t go very far. Its (presumed) recent bombing attack on Saudi Arabia’s oil storage complex with drones that flew below the radar was done with relatively elementary technology.

President Barack Obama did take this inequality on board and, backed up by Russia and the EU, he did forge an agreement with Tehran that rolled back Iran’s nuclear research and removed the threat of it developing weapons (which it probably had no plans to do anyway).

The 2015 agreement was meant to be the entry door to engaging in negotiations with the regime to limit Iran’s provocative interventions in the Middle East. But Obama also missed his opportunities. Early in his tenure Iran offered him an olive branch and he spurned it. He came to push for the anti-nuclear negotiations too late in the day.

Trump, with his perverse urge to sabotage everything that Obama had accomplished, pulled the plug on the deal before it had the time to set itself in concrete.

After 40 years of alienation from and persecution by the US and its allies why should anyone be surprised that Iran has attempted to push back, especially where it can do damage in its backyard?

Its constant hostility towards Israel is because it fears that Israel is working for the downfall of its regime. In Iraq there would be no Iranian presence if there hadn’t been the US-led war of 2003. Saddam Hussein was helped by the US in his war against Iran.

Saudi Arabia has an urge to bring down the regime in Tehran, for reasons part political and part religious. This is why Iran via the Houthis is attempting to bleed the Saudis dry.

But who gets kudos from supporting the Saudi tactics which spare neither women, children or hospitals?

Iran’s relationship with Syria is principally a marriage of convenience by two Shi’ite states which feel threatened by the Middle East’s majority of Sunnis. It does not threaten US essential interests.

Iran and the US have never been further apart. The EU tries to be a moderating force but is cowed by the reach of American economic sanctions.

Yet if the US undermined Iran to the point of destabilizing its economy and its government it would be shooting itself in the foot, unleashing further instability in the Middle East, not least a massive refugee crisis.

Iran can be belligerent but it doesn’t help to constantly confront it.

Obama showed the way with EU and Russian support.

The sooner the US can return to that path the sooner can the Middle East become much more peaceful.