Iran's defiant volley of ballistic missile attacks on Iraqi bases hosting American forces significantly quickened a cycle of escalation that threatens to erupt into a full blown war with the United States.
Iran's attack appeared to shatter the talking points of Trump's political allies that his targeted strike against Qasem Soleimani had reestablished deterrence. Far from stopping a war as Trump promised, last week's attack may have started one.
While the missile strikes represented rare direct fire between Iran and the US, they were not as potent as they might have been given Soleimani's talismanic importance to the Iranian regime. If Trump interprets them that way, it could open an avenue to limit the escalation of the current crisis.
The question now, is how the President, torn between a hatred of looking weak and a new Middle Eastern war he vowed to avoid but seems to have blustered his way into, will react. He could offer insight when he addresses the nation Wednesday morning.
If neither side blinks, America could be on the brink of its first hot war with revolutionary Iran after 40 simmering years of proxy conflicts, bitter rhetoric and short-lived diplomatic thaws.
Or each of the foes could consider their honor preserved after several days of inflammatory exchanges and step back from the cusp of a confrontation that is threatening to spin out of control. Such a step back would not quell tension. It would likely see Iran seek to oust the US from the region and Washington redouble political, economic and diplomatic pressure on Tehran. But it might stop short of the shooting war both sides insist that they don't want.
If it is to be war, it would be one of Trump's own making, and a product of a brash, threatening leadership style carved from an "America First" disdain for traditional US diplomacy by an emotional President who acts on instinct rather than strategy.
It would match Trump -- and his hollowed out national security team, purged of moderating forces who might have stopped him short of this point -- against Iran's theocratic rulers.
It now seems as though Trump's hardline policy towards America's 40-year foe -- triggered by his withdrawal from an Obama-era nuclear deal -- is close to reaching an inevitable result.
The administration says that its "maximum pressure" policy and punishing economic warfare is designed to force Iran back to nuclear talks and to quit its regional misbehavior. It seems to have had the opposite effect.
A war with Iran could further tear the fabric of American political life, amid Trump's impeachment battle, and rebound on the President as he seeks a second term in November's election.
It could set the Middle East ablaze even more so than the Iraq War, unleash assaults by Iranian proxies on American targets and allies and halt the fight against ISIS. Given opposition to Trump's harsh Iran policy among traditional allies, America could find it fighting such a battle alone.
How will Trump respond?
Trump now appears to have two options.
First, he can follow through on his own threats and take another step in the escalatory cycle with what he warned might be disproportionate military force. In this scenario, and given that Iran fired missiles at Americans from its own territory, it seems inevitable the US would target Iranian soil. Islamic Republic pride might dictate another move towards full-on war.
"If Iran does anything that they shouldn't be doing, they're going to be suffering the consequences, and very strongly," the President told reporters in the Oval Office Tuesday.
Much will depend on how the United States evaluates Iran's attacks on the al-Asad air base west of Baghdad and in Erbil in the semi-autonomous Kurdish region of northern Iraq.
Trump could chose to accept Iran's play as its calibrated response to Soleimani's killing and hold back the wrath of the US military. While Tehran did directly fire on American troops, it could have taken steps that were more likely to result in mass US casualties.
But Trump never turns the other cheek. His mantra is when you are attacked, hit back harder -- a philosophy that seems to have informed the stunning shot at Soleimani, which surprised even some members of his own administration.
"Trump has already set a standard that he's going to do a massive retaliation. If he fails to do that I think he looks weak," one source who recently spoke to the President told CNN's Jim Acosta.
A possible pause
Yet the most grave moment of a presidency awash in shallow political controversies also tugs Trump in another direction.
The President's instinct is to withdraw American troops from harm's way everywhere. He sees deployments overseas as a waste of money. He promised the political base to which he remains unfailingly loyal that he was different than predecessors who foundered on foreign entanglements, especially in Iraq.
"We don't want to be there forever; we want to be able to get out. I didn't want to be there in first place, to be honest," Trump said, working through his conflict in the Oval Office.
Defying some expectations, the United States did not immediately retaliate Tuesday.
"Now is the time for patience and restraint," a senior administration official said.
The President seemed to radiate relief that no Americans were killed in the attacks, despite reports of Iraqi casualties.
"All is well! Missiles launched from Iran at two military bases located in Iraq. Assessment of casualties & damages taking place now. So far, so good! We have the most powerful and well equipped military anywhere in the world, by far! I will be making a statement tomorrow morning," Trump tweeted.
Confirmation that no Americans died could offer Trump running room to avoid large-scale reprisal strikes against Iran.
The President decided against making an Oval Office address to the nation on Tuesday night after news broke of Iran's attacks. This potentially wise move spared him from immediately investing prestige in a course of action.
Perhaps the pause will give Trump time to reflect.
Retired Lt. Gen. Mark Hertling, a CNN military analyst, counseled restraint, passing on a lesson imprinted on the nation's recent history.
"It's very easy to fall into a war and start a war, it's a lot more difficult to extract ourselves from one," Hertling said.
The top Democrat on the Senate Foreign Relations Committee, New Jersey Sen. Robert Menendez, on Tuesday urged Trump to step back from confrontation before it is too late
"We are at a critical juncture where we still have an opportunity to be responsible and pursue diplomatic channels," Menendez said in a statement.
"The American people are not interested in getting involved in yet another endless war in the Middle East with no clear goal or strategy."
A key question in the coming days is whether a divide-and-rule President can unite the nation behind him if the situation deteriorates further.
Already there are serious rumblings on Capitol Hill about the administration's refusal to reveal the intelligence that Trump says proves Soleimani was planning "imminent" attacks.
Defense Secretary Mark Esper told CNN's Christiane Amanpour that the intelligence was "more than razor thin" but also argued that Soleimani's "time was due" -- appearing to indicate that his record was as important as his intent.
The debate about timing might seem irrelevant given that there is no doubt that Soleimani was a sworn enemy of the United States with American blood on his hands.
But if the administration used inadequate intelligence as an excuse to eliminate him as part of an ideological Iran policy, it will beg the question of whether the cost justified the risk.
Iran is also playing politics
In coordinating its response to Soleimani's killing, Iran took a noticeably political approach -- seeming to consciously pile political pressure on the President, perhaps in the belief he doesn't want to go down in history for starting a war.
The al-Asad air base was familiar to him — it was where he touched down during his only trip to Iraq in December 2018.
The Iranians also stressed, amid a barrage of bellicose commentary possibly aimed at a domestic audience, that their response was proportionate and not intended to spark a war.
"We do not seek escalation or war, but will defend ourselves against any aggression," Foreign Minister Javad Zarif tweeted, in what was possibly a veiled offer of an informal truce.
Days after a senior State Department official told reporters that -- by killing Soleimani -- the US was talking to the regime in Tehran in language it understands, the Supreme Leader Ayatollah Ali Khamenei seemed to slip into Trump-speak in a statement.
"I said during a speech at the time (of Barack Obama's presidency) that the time for hit-and-run is over. If you hit, you get hit back," the Ayatollah said in an undated video released in Tehran.