Will Iran and the United States go to war?

Under the Trump Administration, a military-backed regime change in Iran is almost unthinkable.

Many pundits around the world concluded six months ago that the assassination of Quds Force leader Qassem Soleimani would lead to a US-led regime change war on Iran in the Middle-East. But Donald Trump will not jeopardize the reputation of his administration by invading Iran, particularly at a time when hostilities between China and the US are getting more heated and after running on a campaign of ending endless wars.

Most important for understanding a possible conflict between Iran and the United States is examining the scope of US military operations in the region today. The United States is currently committed to stabilizing Iraq, looks as if it will completely withdraw from Syria and is currently negotiating with the Taliban for an exit from Afghanistan.

If there is a war between Iran and the United States in the region, it is most likely to happen either in Syria, Iraq or Afghanistan. In Syria, there is an opportunity for Iran to make a quick victory over US forces concentrated on the Syrian-Iraqi border. But as Iran's strategic partners Syria, Russia and Turkey are all involved, this is the least likely of the three scenarios, as a confrontation might jeopardize Iran's relations with its strategic partners.

War between the US and Iran in Iraq is a more possible scenario, and is frightening. It would lead Iraq into its worst state of conflict yet, worse even than when ISIS invaded in 2014 and, unlike a US invasion of Iran's mainland, would likely result in US victory over the Iranians. The Gulf War of 1991 is a good example of the sort of conflict the US would engage in: in 1991, the US drove Saddam Hussein out of Kuwait, destroyed Saddam's military forces but did not invade Iraq and conquer Baghdad. Similarly, a war between Iran and the US in Iraq would drive Iranian proxies and military forces out of Iraq, would destroy Iranian military targets but, after achieving these aims, the US would not proceed to invade Iran.

Afghanistan, however, is where the Iranians and the United States are most likely to engage militarily. Current negotiations look successful between the Taliban and the United States. However, it is possible that with Iranian support, the Taliban would initially agree to the United States' demands until the United States withdraws from Afghanistan. After the withdrawal, the Taliban may indeed march to Kabul and take down the Afghan government.

Such a scenario would propel Afghanistan into its worst instability in decades, and the US would be forced to return to Afghanistan with more military might than ever. But returning to Afghanistan is not straightforward. Since Afghanistan is land-locked, the United States needs entry through a country bordering Afghanistan. Pakistan and Iran both have borders with Afghanistan and have both been hostile to US interests there. Worse, in the midst of a destabilized Afghanistan, the US and Iran might find themselves on opposite ends of an escalated conflict there, with little ability to deescalate tensions.

But unlike in Iraq, an Iran war in Afghanistan gives the advantage to Iran, not to the United States. Iran would not need to invade Afghanistan directly, but merely finance the Taliban to take down the Afghan government. In fact, the Afghan government might secretly negotiate with the Iranians for such a scenario to occur. The Afghan government prefers to have the United States in Afghanistan, and would leverage an Iran-backed Taliban as incentive for the United States to return. That said, an Iran-funded Taliban in Afghanistan is the most possible scenario for US defeat at the hands of Iran.

The Trump Administration will not, under almost any circumstances, invade Iran directly. But as Iran's economy continues to crash, Iran might just decide it has more to gain out of direct military confrontation with the US in a neighbouring country than out of negotiations. This increases the likelihood of more endless war in Syria, Iraq or Afghanistan, and would challenge the Trump Administration's foreign policy as never before.