WASHINGTON • He heard from his generals and his diplomats. Lawmakers weighed in, and so did his advisers.
But among the voices that rang powerfully for US President Donald Trump was that of one of his favourite Fox News hosts: Mr Tucker Carlson.
While national security advisers were urging a military strike against Iran, Mr Carlson in recent days had told Mr Trump that responding to Teheran's provocations with force was crazy. The hawks did not have the President's best interests at heart, he said.
And if Mr Trump got into a war with Iran, he could kiss his chances of re-election goodbye.
However much weight that advice may or may not have had, the sentiments certainly reinforced the doubts that Mr Trump himself harboured as he navigated his way through one of the most consequential foreign policy decisions of his presidency. By his own account, Mr Trump called off the "cocked & loaded" strike on Thursday night with only 10 minutes to spare, to avoid the estimated deaths of as many as 150 people.
The concerns that Mr Trump heard from Mr Carlson reflected that part of the presidential id that has always hesitated at pulling the trigger. Mr Trump has at times pulled back from the use of force, convinced that America has wasted too many lives and too much money in pointless Middle East wars and wary of repeating what he considers the mistakes of his predecessors.
As Mr Carlson and other sceptics have argued, a strike against Iran could easily spiral into a full-fledged war without an easy victory. That, Mr Trump was told, was everything he ran against. And so the President struggled into the early evening, committed to taking action to demonstrate resolve - right up until the moment he called off the warplanes and missile launchers.
The full story of how Mr Trump set in motion an attack and then cancelled it remained to some extent shrouded in mystery even to some of those involved, according to interviews with officials, military officers and lawmakers. As of 7pm on Thursday, senior US officials were told the strike was on, and would be carried out between 9pm and 10pm, or just before dawn in Iran. Within an hour, it was called off.
On Twitter and in an interview with NBC News, Mr Trump attributed his change of heart to a desire to avoid casualties. The generals, he said, said that about 150 people would die. "I thought about it for a second, and I said, you know what, they shot down an unmanned drone, plane, whatever you want to call it, and here we are sitting with 150 dead people that would have taken place probably within half an hour after I said go ahead," Mr Trump told NBC. "I didn't think it was proportionate."
But an administration official privately disputed that account. The 150-dead estimate came not from a general but from a lawyer, according to the official. The estimate was developed by Pentagon lawyers drafting worst-case scenarios that, the official said, did not account for whether the strike was carried out during daytime, when more people might be present at the targets, or in the dark hours before sunrise, as the military planned.
That estimate was passed to White House counsel Pat Cipollone. It was then conveyed to the President by the White House lawyers, at which point Mr Trump changed his mind and called off the strike.