Donald Trump is facing the toughest and most lonely dilemma of his presidency.
The White House's abrupt decision to pull back on retaliatory strikes on Iran that had already been ordered underscores how Tehran's downing of a US drone leaves Trump with no risk-free options. Each conceivable military or diplomatic response is likely to provoke a further Iranian escalation that would deepen the increasingly grave standoff.
The President is caught between Republicans demanding a hawkish response, Democrats warning he could "bumble" into war and Iranian policy hardliners on his own national security staff who welcome the confrontation. There is no obvious outcome that gives him the clear political win that is a frequent motivating force behind his foreign policy ventures.
Asked which way he would turn on Thursday, Trump told reporters, "You'll find out" -- without giving any sign he had settled in his mind on US retaliation.
Attacks on a handful of targets, including Iranian missile batteries but the operation, were set but the operation was called off as it was about to begin, a US official with direct knowledge of the situation told CNN. It was not immediately clear whether Trump approved the operation before changing his mind or if he stopped short of giving final presidential approval and decided against proceeding further with the strikes, which were first reported by the New York Times, or whether some other significant event took place in the region that is not yet publicly known about shifted his calculation.
It's often been remarked in Washington that Trump has been lucky not to face a sudden, serious national security emergency so far in his presidency. Well, his luck has now run out -- though he will get little sympathy from critics who long predicted his hard line Iran policy would precipitate exactly this scenario.
The worsening crisis will subject his chaos-riddled administration to an unprecedented test of cohesion. Trump may need to call on allies he has spent months insulting. His trashing of truth and an amateurish public relations effort to build a case against Iran may undermine his chances of selling potentially dangerous action to the American people.
Which way will Trump turn?
Usually, a good guide to Trump's future action on foreign policy is to identify the course that will most swiftly benefit him politically.
But the current crisis appears to draw two aspects of the President's personal interests into conflict.
Avoiding foreign entanglements is a core principle of Trumpism. The President doesn't even want US in peacetime deployments in allied nations, let alone at war in the Gulf.
But even a "proportional" US military response, like shooting down an Iranian drone or attacking the base that fired the missile that brought down the US aircraft, would likely force the Islamic Republic to up the stakes considerably again. Trump would inevitably be drawn deeper into the quicksand of the Middle East.
The President also has his own image and credibility to consider.
Failing to respond to Iran's escalation would add to a growing impression that Trump's "fire and fury" rhetoric and strongman persona rarely translates into action. He knows that foreign powers such as China, North Korea and Russia are watching carefully. He'd hate to to look weak heading into meetings at the upcoming G20 summit in Japan with Presidents Vladimir Putin and Xi Jinping.
This is a much sharper quandary than when Trump fired cruise missiles into Syria in 2018 after a chemical weapons attack to enforce a red line that former President Barack Obama let slide.
Then, Trump savored a quick political payoff after one-upping Obama, looked tough and knew there was little risk of retaliation that could endanger Americans or deepen the crisis.
None of those easy wins are on offer with Iran.
"He has got a very difficult decision to make," said Jeh Johnson, a former Obama secretary of Homeland Security who was also a top Pentagon lawyer, on "The Situation Room with Wolf Blitzer."
"His instincts are no foreign engagements yet someone took an action against our forces there and the President has an obligation to protect forces deployed in the Gulf, in the Strait."
"He is wrestling with a tough decision. It is much easier to start one of these fights than to end one," said Johnson.
A classic Presidential conundrum
For perhaps the first time, Trump is being forced to agonize over a classic presidential problem -- one that has no good outcomes and ends up on the President's desk because everyone else has failed to solve it.
Trump often has a deeply idiosyncratic concept of the US national interest -- when he takes it into consideration at all on a thorny foreign policy question.
But this is different. American lives may well rest on his response. The nation could be sliding towards a major war with a power that is far more capable than Iraq -- which managed to bog down US troops for a decade. A prolonged conflict with Iran could unleash geopolitical and domestic forces that could destroy his presidency if it goes wrong.
Trump leads from the gut, disdains detail and often appears to handle crises by saying or doing whatever it takes to get to the end of the day. This building crisis requires study, strategic thinking three, four or five steps ahead and an evaluation of the cascade of consequences that could unfold from any course of action.
National security emergencies often stretch an administration to its limits and require a unity of purpose and inter-agency cohesion that Trump has gone out of his way to undermine.
So far, in the hours since an Iranian missile brought down the $110 million surveillance drone over the Gulf of Oman, Trump has been -- perhaps surprisingly -- slow to pull the trigger.
He has controlled his impulsive instincts in an out-of-character show of restraint from a man who Hillary Clinton said should be kept from the nuclear codes as he could be baited by a tweet.
Trump, as other Presidents would have done, sought to buy himself time and political space ahead of Situation Room meetings with military and political advisers. He prudently brought congressional leaders into the loop.
He suggested the incident could have been the work of a "loose" rogue general, dismissing the Washington consensus that Iran was deliberating ratcheting up its leverage to test him.
"I find it hard to believe it was intentional," Trump said.
It was unclear if the President was speaking after seeing intelligence that suggested divides in the Iranian chain of command or was positing a scenario that could offer him a way out of escalating the confrontation with Iran.
One clear problem for Trump is that while he may wish to de-escalate tensions with Iran, there may be little incentive for Tehran to cooperate.
That's because US sanctions under Trump's maximum pressure campaign have strangled the Iranian economy and caused serious deprivation amid the population.
Recent incidents, including the downing of the drone, attacks on shipping in the Gulf of Oman, and the Islamic Republic's warning that it will break international limits on uranium enrichment, appear to be an attempt to impose consequent costs on the US.
So without an alleviation of sanctions -- that Washington is in no mood to offer or a significant offer from Trump to bring Iran to the table -- it may be locked into its current course.
Even then, Supreme Leader Ali Khamenei has said that Trump's decision to pull out of Obama's nuclear deal means Washington can never be trusted in a dialogue again.
Trump could 'bumble into war'
Unusually, Trump's mood on the day after the drone attack appeared to be more in tune with that of Democrats than the Republican senators who rarely break from the President.
House Speaker Nancy Pelosi emerged from an administration briefing of top congressional leaders looking grave. She said she didn't think Trump wanted war but added: "The high-tension wires are up in the region. We must de-escalate."
Pelosi later went to the White House to meet Trump along with the top Senate Democrat Chuck Schumer and other congressional leaders from both parties.
"The President may not intend to go to war here but we're worried that he and the administration may bumble into a war," Schumer told reporters after the meeting.
But the President is already under pressure for a robust military response from Republicans.
"I would encourage forceful action to stop this behavior before it leads to wider conflict," said South Carolina Republican Sen. Lindsey Graham, one of Trump's closest friends on Capitol Hill.
"Doing nothing has its own consequence. If you do nothing, the Iranians see us as weak," Graham said, calling for strikes against Iranian naval vessels in the Strait of Hormuz.
Republican Sen. Marco Rubio of Florida tweeted that while the administration did not want war with Iran, "it has also made clear that it will respond forcefully to an attack."
Washington buzzed with speculation on Thursday about Secretary of State Mike Pompeo and Trump's national security adviser John Bolton who are seen as drivers of the tough US Iran policy.
Critics charge the pair, who replaced officials who opposed Trump's decision to pull out of the Iran nuclear deal, with creating the crisis through their advice to Trump.
But Brian Hook, the US special envoy for Iran, this week insisted that despite Iranian provocations, the administration's policy was working and had weakened Iran.
He fueled an impression that parts of the administration welcome the showdown, after disputing the notion that the Iran deal had at least frozen the question of an Iranian bomb for a decade.
"Rather than wait for all of these things to come to pass in 10 years when Iran is stronger, we have pulled that forward," Hook told a House Foreign Affairs subcommittee on Wednesday.
"I truly believe that everything we are seeing today is inevitable," he said.
This is one problem that will not be solved with a tweet and is asking questions of the President that he has never faced before.
This story has been updated.