The United States has just intentionally bombed a Syrian regime target for the first time since the country’s civil war began in 2011. So far, it has been a limited cruise missile strike targeting one Syrian airbase, causing an as-yet-unknown number of casualties.

"Dozens of Tomahawks were launched against a single Syrian regime airfield,” a Department of Defense official told Vox.

The decision to attack was a direct reaction to the Syrian regime’s Tuesday gas attack that claimed 85 lives, including about two dozen children. Images of the Syrians who suffocated to death seemed to shock President Trump, who spoke Wednesday of the “beautiful little babies” killed in the attack, which he described as “an affront to humanity.”

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Trump went even further Thursday, telling reporters that “something should happen” to Syrian President Bashar al-Assad because of his responsibility for the attack. Secretary of State Rex Tillerson, meanwhile, said Assad would have “no role” governing Syria in the future and that “steps are underway” for a US-led international push to remove him.

If you think all of that sounds like the polar opposite of what you’ve been hearing from the Trump administration until just a few days ago, you’d be right. Take US Ambassador to the United Nations Nikki Haley, who said in March that “our priority is no longer to sit there and focus on getting Assad out.” Or take Tillerson himself, who said in late March that “the longer-term status of President Assad will be decided by the Syrian people.”

All of that has changed — rapidly. The president who campaigned on an “America first” platform of keeping the US out of conflicts that don’t directly impact core US national security interests has now intervened in Syria’s intractable civil war. The president who has talked of building closer ties to Vladimir Putin has bombed the Arab dictator Putin has spent years propping up. And the president who was silent just days ago about Assad’s future is now clearly saying the dictator needs to go.

How we got here

Let’s rewind the tape back to Monday, when reports first began to circulate of a gas attack by the Syrian regime on the rebel-held town of Khan Sheikhoun that killed at least 85 people — including 16 women and 23 children — and wounded more than 350. Videos and photos taken by activists and medics on the scene showed victims choking and fainting, some with foam coming out of their mouths. (Assad’s forces later bombed the medical clinic where many survivors were being treated.)

On Tuesday, with the dead still being counted, White House press secretary Sean Spicer said that the US would look “rather silly not acknowledging the political realities that exist in Syria,” where Assad’s hold on power has been getting stronger by the day — in large part due to Russian military support.

Trump’s own initial comments focused more on his predecessor’s past handling of Syria than on Assad’s possible role in the country’s future. In a written statement, Trump said Assad’s “heinous actions” were a “consequence of the past administration's weakness and irresolution. President Obama said in 2012 that he would establish a 'red line' against the use of chemical weapons and then did nothing.”

There were two notable things about the statement. The first was how politically petty and tone-deaf it was for Trump to bash Obama in the same breath as Assad. The second was that it didn’t say Assad needed to give up power — or that the US was willing to do much of anything to bring that about.

By Wednesday, Trump was singing a different tune. He said Assad’s gas attack “had a big impact on me,” and that “it’s very possible … that my attitude toward Syria and Assad has changed.”

"It crossed a lot of lines for me," Trump told reporters at the White House. "When you kill innocent children, innocent babies, babies, little babies, with a chemical gas that is so lethal, people were shocked to hear what gas it was, that crosses many, many lines, beyond a red line. Many, many lines."

This paired well with tough talk from Haley, who gave an impassioned speech at the UN that same day in which she held up photos of children killed in the gas attack and asked, "How many more children have to die before Russia cares?” — a clear dig at Putin, Assad’s primary overseas backer (and an autocrat whom Trump openly admires).

That set the stage for Thursday, when Trump talked tough on Assad and avoided making another gratuitous dig at his predecessor. Tillerson — without saying so explicitly — implied that the administration would for now basically maintain Obama’s Syria policy, which was predicated on Assad eventually relinquishing power after internationally led diplomatic talks.

For good measure, the secretary of state directed Russia to "consider carefully" its continued support for Assad's government. That’s highly unlikely. Although Putin spokesperson Dmitry Peskov said on Thursday that their support for Assad wasn’t “unconditional,” Moscow has said this many times before, and its support has so far remained just that — unconditional.

Trump’s decision to bomb the Assad regime because of its use of chemical weapons is new. This isn’t the Trump of the recent past.

Yet Trump fashions himself a tough guy, one willing to go where his predecessor would not. So far, this means sending US cruise missiles into Syria. This isn’t the America-first stance of Trump’s campaign; it’s the start of something new and uncharted, one that could potentially escalate to a broader US war against Assad.

This is a momentous moment for the United States and Syria. And we have no idea, as of right now, where it will lead.