Steven Simon and Jonathan Stevenson explain why “there is no plausible reason for the United States to go to war with Iran.” Here they note that Iran could not dominate the region even if it wanted to:

Its capacity to project military strength abroad, however, is quite limited. The idea that Iran could dominate, let alone subjugate, the states on the Arab side of the Persian Gulf is risible [bold mine-DL]. Yet the Trump administration, with Saudi Arabia’s encouragement, insists that Iran controls four regional capitals—Damascus, Sana’a, Baghdad, and Beirut—and has designs on others, such as Manama, the capital of Bahrain. This is a variation on the “Shia Crescent” scenario, which acquired currency about fifteen years ago among wary Sunni governments in the region. There is little evidence of its validity [bold mine-DL]. Iran did help save the Assad regime. But this barely restored the status quo ante, while costing Iran considerable money and casualties, and Hezbollah, its local surrogate, large-scale casualties [bold mine-DL]. Furthermore, while Assad may be beholden to Tehran, he must now also answer to Moscow, which decisively intervened after Iran did and has interests in the region that do not easily coincide with Tehran’s. In Yemen, Iran has, through glorified harassment, merely raised the cost to Saudi Arabia and the UAE of controlling Yemeni politics, without enhancing its strategic leverage there because, among other things, its navy cannot operate effectively in the Red Sea.

Iran does have considerable influence in Iraq, but it was the Bush administration’s overthrow of Saddam Hussein and the subsequent elevation of Iraq’s Shia majority to political dominance that facilitated it.

Simon and Stevenson are absolutely right about all this, and I have said many of the same things over the years. Iran hawks have stoked fears of an Iranian takeover of the region for much of the last decade, and they have promoted the false belief that Iran is “on the march” and creating an “empire” out of its various proxies and allies. The president has even embraced the delusion that Iran would have taken control of the entire Middle East were it not for his election. As the authors show, all of this is utter nonsense. Iranian regional power is quite limited, and its government poses no real threat to the United States.

The fact that our government is obsessed with the “threat” from a distant medium-sized country that cannot harm us would almost be comical if it weren’t so dangerous. Iran hawks have to exaggerate the extent of Iranian power and control to justify their fixation on a state that hasn’t invaded any of its neighbors and has very limited power projection. If Iran is not the would-be hegemon of their fantasies (and it definitely isn’t), their obsession with opposing and attacking it would seem ridiculous if not insane, and so they keep inflating the threat to justify their own irrational hostility. That obsession gains the U.S. nothing but problems, and it has real costs for U.S. interests. A policy of relentless hostility to Iran has left the U.S. increasingly isolated and at odds with some of our most important allies, it has strained our relations with many other countries that do not share the anti-Iran obsession, it has brought our government dangerously close to a new, unnecessary war in the region, and as a result it has further destabilized the region to the detriment of everyone there. The other costs are less obvious, but they are still significant. If the U.S. weren’t wasting so much of its time, energy, and resources on its anti-Iranian obsession, it would be able to pay more attention to far more important regions of the world where the U.S. has real interests. The political capital and allied goodwill that the U.S. has wasted in just the last two years because of the Trump administration’s bankrupt Iran policy could have been used for many other constructive purposes that would actually benefit the U.S. and our allies, but instead they have been flushed down the toilet so that the president could curry favor with reckless Middle Eastern client states and spite his predecessor. In the worst-case scenario, this obsession ends up plunging the region into another war that could be easily avoided if the government could acknowledge that there is no good reason for the U.S. and Iran to fight each other.