63 hours: From chemical attack in Khan Sheikhoun to US missile strike on Al Shayrat airfield

Syrians bury the bodies of victims of a suspected toxic gas attack in Khan Sheikhun, a nearby rebel-held town in Syria’s north-western Idlib province, on April 5, 2017. PHOTO: AFP

PALM BEACH, Florida (NYTIMES) - The decision came on Thursday afternoon (April 6) on Air Force One on the way to Florida. President Donald Trump assembled his National Security Council on his plane, some by secure video link, as the generals made the case that President Bashar al-Assad of Syria had to learn there was a price to pay.

Trump was shaken by photos his staff had shown him of children dying after the Syrian government's chemical weapons attack -far more graphic than those the public had seen - so the president did not need a lot of convincing.

"What happened in Syria is truly one of the egregious crimes and it shouldn't have happened," he told reporters when he poked his head into the press cabin. "And it shouldn't be allowed to happen."

Two hours later at his Mar-a-Lago resort here, Trump gave the order to unleash 59 Tomahawk cruise missiles at Al Shayrat airfield in western Syria, where the chemical weapons attack originated. His generals had given him the option of delaying a day, but Trump chose not to wait.

Here's a timeline of the 63 hours from chemical attack to the US strike:

Early morning, Tuesday, April 4:

The bombs fall on Khan Sheikhoun in the rebel-held territory of Idlib province. Video of the attack quickly surface, showing women and young children gasping for breath and foaming at the mouth as they fight the effects of what officials later say was sarin gas, a brutal nerve agent.

10am, Tuesday:

Trump huddles at the White House with his military and national security advisers for what his aides now describe as an extensive briefing on the attack. The president had questions for his aides, including Lt. Gen. H.R. McMaster, the national security adviser. "He was very interested in understanding better the circumstances of the attack and who was responsible," McMaster later tells reporters.

Trump has a series of meetings on healthcare, the environment and other topics, but aides say the images from Syria - especially those showing the suffering of small children and babies - weigh on him.

Noon, Tuesday:

The first public evidence of the president's concern about the chemical attack comes from Sean Spicer, the White House press secretary, who reads a statement condemning the Syrian government. He also places blame on former President Barack Obama for failing to strike the regime in 2013.

The attacks, Spicer says, are "not something that any civilised nation should sit back and accept or tolerate." But he does not demand that President Assad step down, and dismisses the idea as impractical: "We would look like, to some degree, rather silly not acknowledging the political realities that exist in Syria," he says.

8pm, Tuesday:

At the White House, national security aides to Trump gather for a "restricted deputies committee meeting" to review options. The group - made up of the deputies to the president's chief foreign policy advisers - begin vetting the options with the agencies that would have to carry them out.

Morning, Wednesday, April 5:

Members of the National Security Council arrive at the White House to review the work from the night before. Intelligence and military officials continue to investigate the attack, giving them confidence that Assad is responsible. "That confidence level has just continued to grow in the hours and days since the attack," McMaster later tells reporters. The evidence, he says, is increasingly associated with "the victims that are being treated and confirmation of the type of agent which was used, which is a nerve agent."

Noon, Wednesday:

Trump makes his first public remarks about Syria, telling a group of reporters in the Oval Office that the attacks are unspeakable. As his advisers continue working on details for a military strike, Trump remains uncharacteristically disciplined about his plans. Asked by a reporter whether he intends to take any action with regard to Syria, Trump says: "You will see."

1.15pm, Wednesday:

At a news conference in the White House Rose Garden after a meeting with King Abdullah II of Jordan, Trump says his horror at the images of "innocent children, innocent babies" choked by poison gas in the attack have led him to reassess his approach to Syria.

"It's very, very possible, and I will tell you it has already happened, that my attitude toward Syria and Assad, has changed very much," Trump says, adding later: "It crossed a lot of lines for me. When you kill innocent children, innocent babies, little babies, with a chemical gas that was so lethal," then that "crosses many lines, beyond a red line, many many lines." Without giving away his plans for possible military action - under consideration at this point - Trump acknowledges that "I now have responsibility, and I will have that responsibility and carry it very proudly."

Wednesday afternoon:

Trump convenes a meeting of his National Security Council after lunch with the Jordanian king. For several hours in the Situation Room, the president's top military and national security aides present him with three options for action in Syria. Aides say Trump was looking for something aggressive but "proportionate" that would be sufficient to send a signal - but not so large as to risk escalating the conflict.

"The president asked us to focus on two options in particular, to mature those options, and he had a series of questions for us that we endeavoured to answer," McMaster later tells reporters. Deliberations continue throughout the afternoon as military and intelligence officials focus in part on how they might use missiles to target the airfield used to deliver the chemical weapons. After several hours, the president and his advisers agree to reconvene the next day.

12.05pm, Thursday:

Trump's motorcade pulls out of the White House, headed for Air Force One and then a summit meeting with President Xi Jinping of China at Mar-a-Lago. With him on the plane are McMaster; Stephen Bannon, his chief strategist; Reince Priebus, the White House chief of staff; and Trump's economic advisers.

Trump reconvenes the National Security Council, adding those on the ground via the secure, air-to-ground video connection. His aides later describe Trump's decision-making as deliberate, although he is also driven by emotion at the sight of the atrocities - and with the power to do something about it.

Trump makes up his mind to act, although aides declined to provide more details about the president's thinking and the conversations on the plane.

Spicer fields questions from reporters about the possibility of military action in Syria. " He is being presented with a lot of options," Spicer says. "I would go back and echo the comments the president made in the Rose Garden. He is not one to telegraph those decisions until he is ready to make them."

2pm, Thursday:

With Trump still in the air, Secretary of State Rex Tillerson lands in Florida to greet Xi, who has arrived a few moments earlier on his Air China plane. After the greeting, Tiillerson briefs reporters at the airport about the coming meeting with Xi. Pressed by reporters on Syria, Tillerson says the United States must act. "It would seem there would be no role for him to govern the Syrian people," Tillerson says of Assad, an abrupt turnaround from Spicer's comments some 48 hours earlier. "We are considering an appropriate response for this chemical weapons attack. A serious matter requires a serious response."

4pm, Thursday:

Air Force One lands in Palm Beach and the president is whisked to Mar-a-Lago, where he heads into another meeting with his National Security Council.

By this point, the military options have been winnowed to a Tomahawk cruise missile strike at Al Shayrat airfield in Syria. US intelligence has tracked the planes that carried out the attacks and determined that they were Syrian government warplanes that had departed and returned to the base.

"It was important during the president's deliberations," McMaster says. Aides said Trump was determined to display some form of strength, but also mindful of the difficulties looming with Russia once the strikes became known.

Before the meeting ended, Trump formally gave the green light: The missile strikes were a "go."

7.10pm, Thursday:

From a phone line in a small, nondescript room at the sprawling Al Udeid Air Base in Qatar, the US air war command for the region, US commanders begin warning their Russian counterparts of an imminent strike at the airfield, in compliance with a "deconfliction" agreement with Moscow to try to prevent an unintentional confrontation between the two countries.

But the Americans give the Russians the warning no more than 90 minutes before the strike, according to a US official. In other words it is a notification, not a consultation. The conversation is described as lengthy and the Russians do much of the talking.

7.40pm, Thursday:

At 2.40am local time in Syria, two US destroyers - the USS Porter and the USS Ross - are in position in the eastern Mediterranean. They fire 59 Tomahawk missiles at the airfield.

8.30pm, Thursday:

In Washington and at Mar-a-lago, the president's advisers began notifying foreign leaders and members of Congress that the missile strikes had begun. Vice-President Mike Pence started dialing, as did the secretary of state, the national security adviser and other top aides to the president.

Senator Mitch McConnell of Kentucky, the Republican leader, received one of the calls from Pence. As McConnell later told reporters, the vice-president "explained the rationale, how they were doing it and I thought it made a lot of sense and would be a strike that would be noticed, not some kind of pinprick."

8.40pm, Thursday:

The cruise missile strike targets aircraft, hardened aircraft shelters, radars, air defence systems, ammunition bunkers and fuel storage sites. But US planners avoid targeting any site where they suspect chemical agents might be stored.

Dinner wraps up at Mar-a-Lago. As the missiles are about to hit their targets, Trump pulls Xi away from the other guests and informs him of the strike. Aides describe it as a brief, matter-of-fact discussion.

9.15pm, Thursday:

Trump assembles his national security team and other top advisers in a secure room at Mar-a-Lago after the strikes.

A photograph of the meeting, distributed by Spicer on Friday, shows the president at a small table with McMaster, Priebus, Bannon, Tillerson and Jared Kushner, the president's son-in-law and adviser. Others, including Treasury Secretary Steven Mnuchin, Commerce Secretary Wilbur L. Ross and Dina Powell, the deputy national security adviser for strategy, are also in the room.

9.43pm, Thursday:

Reporters are called in for a statement that Trump delivers to announce the strikes, which he calls an action that is in the "vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons." The statement is organised so quickly that reporters are unable to broadcast it live. They record it to tape to be aired soon after; the rush also means the sound quality is poor.

But the import of the president's words is clear.

"We ask for God's wisdom as we face the challenge of our very troubled world," Trump says. "We pray for the lives of the wounded and for the souls of those who passed. And we hope as long as America stands for justice, then peace and harmony will in the end prevail."

Join ST's Telegram channel and get the latest breaking news delivered to you.