It falls to America to rally the world to act, or to act on its own, in the face of the savagery.

In a slaughter for which there must be swift and sure consequences, Syrian dictator Bashar Assad, who has already killed hundreds of thousands of Syrians, has yet again unleashed chemical weapons, breaking, once more, the international law of war. He murdered children. He burned their lungs, left them gasping for air.

And then, according to witnesses, a regime airstrike attacked a clinic treating victims, one called to duty because the area’s largest hospital was hit by Assad’s air force just two days before.

In response, President Trump has rightly condemned the attack — and unhelpfully placed responsibility in part at the feet of Barack Obama, for failing to act in the face of a 2013 chemical weapons attack.

Blame-shifting will not protect a single Syrian or send a message to other dictators who might similarly tempt the will of the world.

Chemical weapons are banned under global treaties to which the U.S. and Syria are signatories. As the world’s most powerful nation and its putative moral leader, it now falls to America to rally the world to act, or to act on its own.

The victims this time were in Khan Sheikhoun, with more than 70 dead and many more injured.

Reports say more than 100 people suffered spasms, paralysis, fluid in the lungs and foaming at the mouth — all symptoms consistent with sarin nerve gas, the same poison that killed more than 1,000 four years ago.

To see the images is to shudder. But for human beings with a moral compass, looking away is not an option.

Given Assad’s brutal campaign to kill enemies of all stripes, this dark day was predictable. Yet from the start, Trump and his administration, singularly focused on the evil that is ISIS, and strangely cozy with Vladimir Putin’s Russia, have softened the U.S. posture toward the dictator.

Days ago, Secretary of State Rex Tillerson said the “longer-term status of President Assad will be decided by the Syrian people” — parroting the precise language of Assad’s apologists. UN Ambassador Nikki Haley said America’s “priority is no longer to sit there and focus on getting Assad out.”

Trump today joined a chorus of sickened world leaders, declaring that Assad’s “reprehensible” attack “cannot be ignored by the civilized world.” In the next breath, he called “the heinous actions” “a consequence of the past administration’s weakness and irresolution.”

Only one man sits behind the Resolute Desk in the Oval Office now. It falls to him alone to demonstrate genuine strength in the face of criminal brutality.