The long, shape-shifting shadow war between the United States and Iran’s Islamic Republic has taken a pivotal turn with the death of Qasem Soleimani, an infamous and iconic Iranian military commander, in a US drone strike. By killing the architect of Iran’s expanded influence across the Middle East, the Trump Administration has escalated simmering tensions with Tehran from an economic onslaught to an act of war that is likely to instigate a dangerous and unpredictable Iranian backlash.But Iran’s instinct for self-preservation means that the Islamic Republic is unlikely to lash out blindly or impulsively. Iranian leaders are well-practised at calibrating retaliation around their real interests, which ultimately concern the survival of their regime, and will likely target reprisals with deliberation and precision. Tehran has historically absorbed major blows and setbacks without immediately yielding to the temptation to strike back in indiscriminate or reckless style — instead choosing to nurture resentments and bide its time. This is how it acted, for example, after the accidental US downing of a civilian airliner in 1988 or the 2008 killing of key Hezbollah operative Imad Mughniyeh. In each of these cases, Tehran avenged its dead with carefully planned attacks that took place months or even years later.More recently, witness what has happened since Donald Trump’s May 2018 withdrawal from the Iran nuclear deal and reimposition of severe US sanctions on Iran. The early, often melodramatic predictions of catastrophe proved premature. Tehran waited a full year, assessing its options before launching carefully calibrated counter-attacks in and around the Persian Gulf, such as pinprick attacks on tiny tankers, easily reparable damage to a Saudi pipeline, reversible violations of its obligations under the nuclear deal, and a more significant but still precise attack on the world’s largest oil-processing facility. And even then, Iran’s pushback appeared to be designed to avoid civilian casualties or catastrophic economic damage, while signalling unequivocally Iranian capability and will.So don’t be surprised if it takes time for the shoe to drop. Now, as then, Iran’s leaders will reserve their vengeance for the time and place of their own choosing, aiming for the option that promises the best prospects for punishing Trump, enhancing their own advantage and alleviating the siege on their economy. After all, they have a rich field to choose from, with prime positions and well-oiled partners across the broader Middle East. Iran has already signalled it will soon announce new breaches of the nuclear deal that Trump discarded.There will be other reverberations around the region that may not need an explicit green light from Tehran, just because of Soleimani’s stature. He was the region’s most influential power broker, at least as instrumental in shaping Iraq’s political landscape as he was in managing the ground campaign against the Islamic State there and in Syria. Senior officials from Iran’s neighbouring adversaries are advocating diplomacy and bracing for potential repercussions.But even Soleimani is not irreplaceable. His painstaking self-promotion as a seemingly omnipresent and invincible architect of Iran’s regional posture also fostered a persistent tendency among Western media and analysts to overstate his centrality. In fact, Soleimani was a creature of the well-developed bureaucracy of Iran’s security establishment, one that has weathered numerous losses of its commanders on the battlefield since the earliest days of the revolution.The Quds Force and the Revolutionary Guard have a deep bench of experienced commanders who can assume Soleimani’s responsibilities, and the quick elevation of Soleimani’s longtime deputy, Esmail Qaani, to replace him is meant to reinforce the continuation of business as usual. The Islamic Republic’s endurance three decades after the death of its charismatic founder, the Ayatollah Ruhollah Khomeini, is a testament to its insulation against reliance on any single individual.There is little evidence that the Trump Administration has mapped out a strategy for managing such a protracted, unpredictable confrontation with Tehran. Soleimani’s death on what has effectively become his home turf in post-Saddam Iraq — alongside a key Iraqi partner — and the capture of leaders of the most powerful pro-Iranian militias in the country has dire implications for US presence there. The strike also leaves the government in Baghdad, already debilitated by months of protests over corruption and Iranian influence, in an even more precarious position. Is there a plan for managing the fallout in Iraq, beyond the hasty call for Americans to flee the country?What will this mean for the nascent progress in de-escalation of the war in Yemen and the devastating humanitarian crisis that has accompanied it? How does Washington expect to mobilise a diplomatic coalition to address the forthcoming total collapse of the Iran nuclear deal, particularly at a time of revived frictions with a nuclear-armed North Korea? Unfortunately, there is nothing in Trump’s track record that builds confidence around his administration’s capacity for foresight or realistic contingency planning.In the short term, Tehran is predictably indulging in an opportune excuse for whipping up nationalism. The Government quickly declared three days of public mourning, and a united front of Iranian political figures has denounced American aggression and pledged vengeance. The unusually large crowds that swelled Friday prayers offer a welcome respite for a regime after a season of significant unrest and the fallout from a particularly fierce round of repression that silenced the streets in November — and, for a week, the entire country’s internet connection.That internal instability still looms large for Iran’s leadership. Even on the day that Soleimani was killed, a pro-government news site featured an opinion poll — albeit of uncertain reliability — that reports dismal public support for the system, at least among residents of the capital: 56 per cent expect to continue protesting, 66 per cent assert they won’t vote in the parliamentary elections next month, and 81 per cent are dissatisfied with conditions in the country.Tehran is facing an unexpected dilemma. In the past few months, Iran has enhanced its leverage with escalating retaliation, based on an increasingly confident gamble that Trump’s election-year aversion to initiating another Middle Eastern war would constrain the US response. Washington’s sudden tolerance for risk upends that calculus. The war that was “imposed” on Iran by Iraq’s 1980 invasion helped to consolidate the revolutionary regime, but trying to take on a superpower today would almost inevitably ensure its demise.But the Trump Administration would be wise to avoid any precipitous victory laps. There are simply no easy solutions to the challenges posed by Iran. Soleimani’s death will almost inevitably degrade the environment for American interests and allies in the region significantly. Neither Trump nor Tehran may really want a war, but each side has proved unwilling or incapable of detouring from a path that will almost inexorably precipitate a much wider and more costly conflict.• Suzanne Maloney is deputy director of the foreign policy programme at the Brookings Institution and a senior fellow in Brookings’ Centre for Middle East Policy