On August 20, 2012, then-President Barack Obama told a group of reporters the use of chemical weapons by Bashar al-Assad’s regime in Syria would cross his “red line.” A year later, almost to the day, Syrian forces killed more than 1,400 people with sarin gas, a particularly horrifying chemical weapon that can cause paralysis, convulsions, or death.

Obama didn’t respond immediately. Instead, a month later, he agreed to a deal with Russia to remove and destroy 600 metric tons of Syria’s chemical weapons stockpile. That would, in theory, make it impossible for Assad to gas his own people, though he could still kill them using conventional weapons.

Obama and his second secretary of state, John Kerry, hailed the accord as a historic way to end Assad’s chemical weapons program without firing a single shot. “It turns out we’re getting chemical weapons out of Syria without having initiated a strike,” Obama told an audience in the Philippines four years ago. “With respect to Syria, we struck a deal where we got 100 percent of the chemical weapons out,” Kerry stated during a July 2014 appearance on Meet the Press.

Four years after Kerry’s Syria comments, President Donald Trump, along with allies France and the UK, launched 105 missiles on Friday at three Syrian targets to punish the regime for killing more than 40 people in an April 7, 2018, chlorine attack. That was the second time Trump authorized strikes on Syria after a chemical attack.

Clearly, Assad kept some of his stockpile and continued to use chemicals with nonmilitary uses — like chlorine, which can cause respiratory problems — on his people. Human Rights Watch has cataloged about 85 chemical weapons attacks in Syria since the August 21, 2013, strike, most of them perpetrated by the regime.

That makes one thing very clear: Assad’s continued use of chemical weapons offers even more evidence of how badly the Obama administration misjudged and mishandled the “red line” moment. It’s one of the biggest problems Obama left for the current occupant of the Oval Office.

Obama-era officials, however, still think the deal was a success. “We enforced the red line diplomatically, not militarily, and far more effectively than if we had used force,” Antony Blinken, a top Obama State Department and White House official, told me. “The subsequent use of chemical weapons by the regime shows that had we proceeded with the limited strike in 2013, it probably would not have deterred future use,” he said.

Trump, however, has opted to use force. Crucially, he didn’t respond to every chemical attack in Syria, although he vows now to keep the pressure on Assad. “We are prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents,” he said from the White House on Friday night.

It’s unclear what effect, if any, Trump’s missile strikes will have on Assad’s ability and willingness to use chemical weapons again. But the fact that Trump has to deal with Assad’s chemical weapons program at all shows Obama’s bet didn’t pay off.

Why Obama didn’t attack Syria

The Long Game, former top Obama national security official Derek Chollet’s 2016 book about Obama’s foreign policy, outlined the last administration’s reasons for not bombing Syria. “[T]here were many concerns about the danger to American pilots (Syria had one of the most sophisticated air defense networks in the world), as well as the possibility of escalation. Everyone understood the risks,” he wrote. “There was no question the US had the capability to act decisively, but there was deep uncertainty about where military intervention would lead.”

And as Obama himself said in an April 2016 interview with Jeffrey Goldberg of the Atlantic, attacking Syria might eventually force America’s long-term involvement in the civil war. That made him hesitant to intervene.

Trump’s two operationally successful military attacks, however, put a massive dent in that argument. First, the US carried out both strikes without losing any troops or equipment. Second, the feared Syrian air defense system proved feckless against Western airpower, shooting roughly 40 missiles after the US-led attack last Friday. Third, Trump’s strikes were limited and for now have not provoked a broader conflict with Assad’s backers in Syria, Russia, and Iran.

That’s not to say Trump’s strikes have done much to date. “I do not expect the strike to change Assad’s behavior,” Randa Slim, a Syria expert at the Middle East Institute, told me. “He will use chemical weapons again when his forces are cornered and are unable to clear territory,” she continued, adding that “Assad never felt threatened” by Friday’s attack.

Mara Karlin, a former top Obama Pentagon official, told me that strikes like Trump’s “can be done” because they are “not operationally difficult. The question is why and for what purpose?”

It’s therefore not fair to say Trump’s two attacks in two years have succeeded in stopping Assad — far from it. But it is fair to say Obama didn’t change anything either.