If the United States goes to war with Iran, then it will be a war of choice—Donald Trump’s choice. By ordering the killing of Maj. Gen. Qassim Suleimani, the president ensured that Iran’s leaders would retaliate against U.S. interests in some shape or form. Trump could not have anticipated exactly how Iran’s leaders would exact their revenge but he knew that a significant military reprisal was possible. And while there are encouraging signs that both sides are now keen to reduce tensions, the risk of Trump pushing America into a devastating war with Iran remains unconscionably high.

When Trump came to office, America’s relationship with Iran was fraught. The two countries had existed in a state of unconventional warfare for some time but it was a struggle waged by proxies and in the shadows—rarely with the risk of their regular armed forces coming to blows with one another.

The situation was far from perfect. It certainly did not amount to peace. But there was at least the prospect of an improved relationship. Most obviously, the Iran nuclear deal, which Tehran was in broad compliance with, could have served as the basis for a more ambitious regional detente, especially given that Trump was elected on a platform of initiating a military drawdown in the Middle East. Thus, it was not unthinkable that the United States and Iran could have found ways to “deconflict” in theaters such as Iraq, Syria, and Yemen.

A truly “America First” foreign policy would have adopted a single-minded focus on U.S. security. It would have meant reducing entanglements in the Middle East, seeking diplomatic solutions to the myriad disagreements that exist between the two sides, while still guarding against Iranian predations on a “targeted-balancing” basis, such as by investing in intelligence and cybersecurity. Trump could have used Saudi Arabia’s barbaric murder of U.S.-based journalist Jamal Khashoggi and domestic revulsion at Riyadh’s war in Yemen to justify a rebalance of forces in the Persian Gulf, with the U.S. pursuing the role of an off-shore balancer rather than an omnipresent security manager.

This is the opposite of what Trump has done. Instead of shrinking America’s footprint in the Middle East, Trump has maintained—and in some cases, expanded—military commitments in the region. His administration has set back the cause of diplomacy by pulling out of the Iran nuclear deal and hollowing out the State Department. And Trump has doubled down on the alliance with Iran’s regional nemesis Saudi Arabia. 

Then came the assassination of Suleimani, a conventional military attack on a high-ranking Iranian official—by some accounts, the second most powerful man in Iran. Thankfully, Iran’s leaders chose to respond to Suleimani’s death with relative restraint, firing missiles at U.S. positions in Iraq but taking steps to minimize risk to life (in the event, no casualties were recorded). Iran’s leaders have now professed their desire for a de-escalation of tensions with the United States, a sentiment echoed in Trump’s subsequent speech from the White House.

But Trump could not have known in advance that Iran’s reaction to the killing of Soleimani would be bloodless. A more terrible attack was possible and may still come. How would Trump have responded to Iranian forces killing American soldiers or civilians? How would he respond to such a thing if it happened tomorrow, whether by design or miscalculation? How could he respond?

By choosing to escalate the conflict with Iran, Trump has put the United States in a position where war could easily become unavoidable depending upon how Iran and its proxies conduct themselves going forward. This is tantamount to waging a war of choice and cannot go unchecked.

As political scientist Bruce Buchanan has argued, retroactive accountability for wars of choice is rarely effective. What is needed is a robust political intervention during the heat of the moment to cool passions and propose more sober policy options. This is a job that Congress, the media, and the voting public must now undertake in unison.

In Congress, the focus must remain on the administration’s decision to kill Suleimani. Why was this incendiary action ordered? Officials point to the fact that Suleimani was the mastermind of countless civilian deaths, plus those of American soldiers. That is true but it is beside the point. Iran’s regional network of proxies did not die with Suleimani nor did Tehran’s interest in promoting a favorable balance of power in the Middle East. Assassinating the head of the Quds Force will not urge Iran to adopt a more pacific foreign policy any more than the death of a high-ranking U.S. official would convince Americans to retreat into isolationism.

The only possible justification for killing Suleimani is that his assassination was essential to prevent an imminent attack on U.S. forces. This, of course, is one of the primary talking points being advanced by the Trump administration. But it should not be taken at face value. Indeed, scant evidence has been offered in support of the claim.

In this regard, there are some historical parallels with another American war of choice: the Mexican-American War of 1846–1848. Back then, President James Polk precipitated war with Mexico by sending forces into a disputed region along the U.S.-Mexico border. He claimed casus belli when, as expected, Mexico retaliated by killing members of the expedition on soil that Polk portrayed as American territory. The status of the land in question was, in fact, undetermined—a point that Polk eventually conceded, albeit once the war was already in motion.

While it would be wrong to overstretch the similarities between Polk and Trump, the basic dynamic is the same: undertaking a provocative action and committing the nation to war dependent upon the adversary’s response. In Polk’s case, war ensued. In Trump’s case, it has not—yet.

The Mexican-American War was recognized as a war of choice at the time. Former president John Quincy Adams denounced Polk’s cynical maneuvering as “outrageous” while future president Abraham Lincoln proposed a succession of so-called spot resolutions to the House of Representatives. The resolutions poked holes in the president’s false assertation that the “spot” on which American blood had been shed was really U.S. soil. While hostilities were still ongoing, the Whig majority in the House of Representatives even adopted a resolution to condemn the war as “unnecessarily and unconstitutionally begun by the President of the United States.”

Of course, the Whigs never succeeded in stopping Polk’s war with Mexico. But the most eloquent among them at least made the critical argument that wars of choice are illegal and must be stopped. Today, Democrats and patriotic Republicans must go further by using every legislative means at their disposal to restrict Trump’s freedom of action and encourage the pursuit of diplomacy. Tim Kaine’s new War Powers Resolution is a good place to start. It might stand a chance of passing if Mike Lee (R-UT) can persuade his fellow Republicans to endorse the measure.

By definition, wars of choice are not inevitable. They are the products of intentional decisions. The way to avoid wars of choice is thus to wrest the decisionmaking process away from the reckless and place it in the hands of those who are disposed towards peace. No task could be considered more urgent.

Peter Harris is an assistant professor of political science at Colorado State University. You can follow him on Twitter:@ipeterharris.

Image: Reuters