What is the likelihood that Trump himself would authorize military action against Iran’s nuclear sites or military assets? One of Trump’s core beliefs, taught to him by his former lawyer Roy Cohn, is “When attacked, hit back harder.” While it remains to be seen how a philosophy born out of New York City real estate quarrels can be applied to complicated geopolitical disputes, throughout his campaign and his first weeks in office Trump’s decision making has been marked by impulsiveness more than restraint. How will he react if Iran continues to defy him despite his repeated taunts and tweets?

Trump’s confrontational style is coupled with a core national-security team that is universally cynical about Iran. Flynn, Vice President Mike Pence, CIA Director Mike Pompeo, and Elliott Abrams—whom Trump was reportedly, until recently, considering for deputy secretary of state—were all outspoken opponents of the nuclear deal. Last fall Abrams advocated “sinking an Iranian ship” to show resolve. While Mattis has not recommended scrapping the nuclear deal, he has called Iran “the single most enduring threat to stability and peace in the Middle East.”

In addition to concerns that Trump’s social-media outbursts may cause an inadvertent conflict, serious observers also worry that Trump could use either a terrorist attack or an external conflict—preferably with a longstanding Islamist adversary—to expand his power. Trump’s strategic advisor Steve Bannon said in November 2015 that Islam was “the most radical” religion in the world and “we’re clearly going into … a major shooting war in the Middle East again.”

To those looking for “shooting wars” in the Middle East, Iran provides an unparalleled opportunity. On numerous occasions over the past two years the U.S. Navy has fired warning shots against Iranian Revolutionary Guard patrol boats in the Persian Gulf and interdicted shipments of weapons bound for Yemen’s Houthis, whose recent attack on a Saudi ship was allegedly intended for the United States. In essence the opportunities for conflict with Iran are numerous and interrelated: An unraveling of the nuclear deal could trigger a regional war, or a regional war could trigger an unraveling of the nuclear deal.

Step 7: Repercussions

In one of his final interviews before dying at age 101, Kennan reflected that "Anyone who has ever studied the history of American diplomacy, especially military diplomacy, knows that you might start in a war with certain things on your mind as a purpose of what you are doing, but in the end you found yourself fighting for entirely different things that you had never thought of before. War has a momentum of its own, and it carries you away from all thoughtful intentions when you get into it. … War seldom ever leads to good results."

The chain-reaction of even “targeted” military strikes on Iran’s nuclear facilities would be unpredictable, enormous, and long-lasting. Hundreds of articles have been written over the last decade assessing its potential impact. Among its many retaliatory options Iran has the power to either attack, or potentially activate sleeper cells in, the oil-rich, predominantly Shia eastern province of Saudi Arabia, sending energy prices skyrocketing. Iran may also feel unrestrained attacking U.S. forces in the region, (mis)calculating that Trump is unlikely to respond given the American public’s fatigue with wars in the Middle East.