No one can predict how the US war with Iran will unfold | Rajan Menon and Daniel R DePetris

Last week, during his State of the Union addresses on Tuesday and Friday, just before the launch of Operation Epic Fear, Donald Trump laid out his case for an attack on Iran.

The US president laid out a lengthy indictment of the Islamic Republic of Iran, dating back to the 1979 revolution: the takeover of the US embassy in Tehran, support for terrorism, brutality against its citizens and support for proxies who killed Americans.

Above all, Trump highlighted the peril the United States and its allies would face if Iran built nuclear bombs. Despite the lack of intelligence confirming this information, he claimed that he would soon have a missile capable of reaching American territory.

Despite this litany of complaints and his characterization of the Iranian government as “evil,” Trump sent his envoys to Geneva to negotiate with Tehran over its nuclear program. After three rounds, Trump grew tired of diplomacy and blamed the Iranians for refusing to say the magic words: Iran will not become a nuclear weapons state. In fact, senior Iranian officials have done this repeatedly. “Iran will under no circumstances develop nuclear weapons,” Iranian Foreign Minister Abbas Araghchi tweeted on February 24.

Beyond that, Iran made significant concessions during the negotiations. Oman Foreign Minister Badr Albusaidi, who mediated the Geneva negotiations, said Iran had agreed to reduce uranium enrichment below 3.67% – the cap stipulated in Tehran’s 2015 deal with the Obama administration – and to allow international nuclear inspectors to return to the country with full monitoring powers. The Iranians went even further by agreeing not to accumulate or stockpile enriched uranium.

If Trump had been smart, he would have pocketed these unprecedented concessions, claimed victory, and bragged – rightly – about getting a better deal from Iran than Barack Obama got. But Trump’s real motive was much more ambitious: the fall of the Islamic Republic.

In January, as Iranian security forces violently suppressed nationwide protests, Trump urged the Iranian people to “take back your institutions” and assured them that “help is on the way.” Last Friday, an hour after the United States and Israel launched their second bombing campaign against Iran in less than a year, he again called on Iranians to “take control of your government” once military operations end and not waste what could be “your only chance for generations.” Israeli Prime Minister Benjamin Netanyahu, who may be more determined than Trump to topple the Islamic Republic, has made similar calls.

In retrospect, the Trump administration’s nuclear negotiations with Iran look more like a box-checking exercise than a genuine effort to resolve the nuclear problem. Even if Iranian officials had agreed to end all uranium enrichment, war would likely have occurred given the maximalist goals of Trump and Netanyahu. The talks may have been designed to demonstrate that Trump had tried diplomacy before deciding on another war.

Understanding that what Trump really seeks is the destruction of the Islamic Republic, its leaders – now under fire – will not collapse without a fight to the end, regardless of the broader consequences. The assassination of Ayatollah Ali Khamenei, “the supreme leader of Iran for 37 years,” showed them that the very existence of the Islamic Republic is at stake.

The war has already turned regional: Iran is attacking Arab states aligned with the United States in the hope that they will pressure Trump into signing a ceasefire. In addition to firing missiles at Israel in retaliation, Iran has attacked Bahrain, Kuwait, Saudi Arabia, Qatar and the United Arab Emirates, which are home to various U.S. military installations. As the war continues, Iran could make the situation even worse by blocking the Strait of Hormuz, through which about a fifth of the world’s oil reserves pass each year. The shockwaves would be felt around the world.

Trump and Netanyahu are betting that Iranians will rise up en masse, as they did in January, and end clerical rule. But every time Iranians take to the streets, Iranian security forces crack down fiercely. If protesters take to the streets again, the government will be even more ruthless: it understands that everything is now at stake.

Trump called on the Islamic Revolutionary Guard Corps and Iranian police to lay down their arms in exchange for “total immunity,” but they could instead stand with the regime. The mass protests that have taken place in Iran over the years and the jubilation over Khamenei’s death in some parts of the country prove that many Iranians insult their government. Yet it would be a mistake to believe that he lacks broad support and rules solely through fear and force.

Neither the United States nor Israel will deploy ground troops, but they cannot destroy the Iranian state through airstrikes and missiles alone. This will require sustained resistance on the ground. By calling for a mass revolt, they are actually asking unarmed Iranians to serve as their ground troops.

If “regime change” occurs, it will not necessarily result in stability. The American record regarding such enterprises is hardly reassuring. In Iraq, Libya and Afghanistan, state collapse has not produced stability, much less democracy – but prolonged anarchy, intrastate violence, refugee flows and the spread of terrorism across borders.

Iran is larger, more populous and more strategically located than any of these countries. Its territory exceeds that of France, Germany and Spain combined. It straddles vital energy corridors and its 93 million residents comprise diverse ethnic and political constituencies with competing visions for the country’s future. A sudden power vacuum in such a context could cause unrest.

If a war to overthrow the Islamic Republic produces disorder rather than order, its consequences – especially for Iranians – could dwarf the upheavals that followed previous wars of regime change. Instability cannot remain confined to its borders; this could ripple across the Middle East and disrupt global energy markets.

Can anyone predict how this war will play out? No. This includes American and Israeli policymakers. A war, once started, can produce all kinds of unforeseen consequences, some of which prove uncontrollable and long-lasting.

• Rajan Menon is professor emeritus of international relations at the Powell School of the City University of New York and a senior fellow at the Saltzman Institute of War and Peace Studies at Columbia University. Daniel R DePetris is a member of Defense Priorities and a syndicated foreign affairs columnist at the Chicago Tribune.