If anyone was foolish enough to believe Syria in 2013 when the country promised to stop producing chemical weapons and disclose its existing stockpile, those fantasies can be put to rest. This week saw the worst chemical attack in years against innocent men, women and children in Syria — almost certainly executed by the nation’s tyrant, Bashar al-Assad. (Of course, he’s spent the last six years killing his people in all sorts of ways.) Now the question is, does anyone believe the U.S. (or anyone) will do anything about it? And is humanitarian concern enough?

The dead, including children, numbered in the dozens, with many more injured due to what experts say appears to be a nerve agent such as sarin — the same agent used in the 2013 attack near Damascus. That 2013 attack followed Barack Obama’s famous “red line” threat in 2012, when he indicated if Assad used chemical weapons the U.S. would respond, possibly militarily. Well, Assad did, and Obama didn’t. Instead, Obama took Assad’s word that he would give up his chemical weapons stockpile — and, worse, he relied on Russia to keep Assad in line. That would be the same Russia now undermining American elections, according to the same Obama and his cohorts.

In 2014, then-Secretary of State John Kerry boasted of his deal with Russia and Syria, “We got 100% of the chemical weapons out.” Evidently not.

It’s little wonder, then, that in the aftermath of the latest attack, President Donald Trump — not known for his tact — pointed a finger at Obama, stating: “Today’s chemical attack in Syria against innocent people, including women and children, is reprehensible and cannot be ignored by the civilized world. These heinous actions by the Bashar al-Assad regime are 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.”

First of all, the appropriate response of a sitting president to a chemical attack is not to blame the preceding president. We condemned Obama’s incessant blame-shifting; Trump’s isn’t much different. Beginning January 20, 2017, America’s action, or inaction, now rests on Trump’s shoulders.

That said, Trump is right on the merits — Obama did nothing in Syria after having created a vacuum in Iraq that led to the rise of the Islamic State. The terrible reality in the Middle East that Obama created now greatly complicates any U.S. involvement.

It’s still anyone’s guess what action Trump might take. While he blasted Obama for not holding to his “red line” (and, indeed, promising consequences but not following through isn’t the best way to show strength, in case anyone is still wondering), Trump was adamant in 2013 in demanding Obama not take military action against Assad. Thanks to the glories of the Internet and social media, Trump’s tweets calling on the U.S. to stay out of Syria are preserved for posterity.

Despite blaming Obama, as recently as last week Trump was following the Obama playbook regarding Syria, saying Assad’s removal was no longer U.S. priority. Instead, the U.S. would focus on fighting the Islamic State and hope the Syrian people would deal with their president.

As M.G. Oprea writes, “This was reported as a shift in policy from the Obama administration. Technically this is true, but in reality, the Obama administration held essentially the same view of Assad. While Obama kept up the rhetoric about a political transition of power, little indicates he would have been willing to spend the political and financial capital necessary to make this happen.”

Indeed, as the world — including our enemies — knows, if there’s one thing Obama mastered, it was empty rhetoric.

But it appears there might be a shift — not merely from the de facto policy of the Obama administration but also from Trump’s policy a week ago. As The Wall Street Journal reports, Trump said the latest attack crossed “many, many lines, beyond a red line.” And while he didn’t provide specifics, he intimated a policy shift could be coming. “That attack on children … had a big impact on me. Big impact,” he said. “That was a horrible, horrible thing. It doesn’t get any worse than that. My attitude toward Syria and Assad has changed very much.”

Of course, one might wonder how the Damascus attack in 2013 — which killed more than 1,000 people, including hundreds of children — didn’t change Trump’s attitude toward Assad far before now. But perhaps the weight of 1600 Pennsylvania Avenue is finally beginning to hit him with the realization that Twitter wars are no substitute for real leadership. Indeed, Trump noted regarding Syria, “It is now my responsibility.”

What that means is still unclear, both from him and in terms of what American policy should be. The question of whether removing Assad is in U.S. national security interests is a murky and complicated one. Yes, Syria has become a breeding ground for Islamic State terrorists, but removing Assad might not change that. It didn’t fix Libya to remove Moammar Gadhafi, but that’s also because Obama’s effort there didn’t even reach the level of being called half-hearted.

And that’s not the only question. There is also a lot to this story that really has nothing to do with Assad or ISIL and everything to do with Russia and Iran. That stuff rarely comes to the surface. The chess-level debate is in the war room. The tic-tac-toe stuff is what makes the press.

In any case, this much is clear: Trump’s action — or inaction — regarding Assad will likely set the stage for how the world views America’s new commander in chief for years to come.