Gayle Tzemach Lemmon is a senior fellow at the Council on Foreign Relations and author of the New York Times best seller, "Ashley's War: The Untold Story of a Team of Women Soldiers on the Special Ops Battlefield." The opinions expressed in this commentary are hers.

(CNN) Pictures of little ones with barrettes in their hair, diapered bodies limp and nearly lifeless, hanging over a loved one's outstretched arms. Curly haired children tucked under gray medical blankets wearing masks to protect their faces. Toddlers working to breathe as medical personnel place nebulizers over their mouths and try to get their respiratory systems working once more.

These are the images coming out of Syria today. They are seizing the world's attention and demanding their viewers feel their horror. And the worst part is, we've seen images like them many times before. What is different now is that the war is entering year six, and it will be up to the Trump administration to respond.

For years, medical personnel, activists and Obama administration policy advisers talked about chemical attacks and how the Assad regime was unleashing them on civilians -- little ones, moms, dads, anyone in the areas held by opposition fighters. And, for years, the world has talked about how horrible they are, passed resolutions about their barbarism and even spoken of "red lines," while little actually ever happened to stop them.

Ask the American doctors in the Syrian American Medical Society, and they will tell you this is all entirely predictable -- and it has been happening in plain sight. More than a year ago, SAMS issued a report titled, " A New Normal: Ongoing Chemical Weapons Attacks in Syria ." Its opening sentence was, "The use of chemical weapons is illegal and immoral, yet has occurred in Syria with impunity for the past three years."

And it is hardly doctors and activists alone who have documented the sustained use of chemical attacks against civilians. The United Nations found evidence of "chlorine gas attacks on civilians" by the Syrian air force in Syria between 2014 and 2015. (The Syrian military said it was not responsible for Tuesday's carnage.)

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But now these images have forced the world to face a moment -- yet another moment -- of decision as the Syrian civil war stretches into its second half decade. The attacks may not be new, but the latest pictures documenting their savagery make them far harder to ignore.

How many images of toddlers struggling to survive in the wake of a chemical attack can the world take? Right now, the answer is, many. And the question on the table is whether that answer will change in the coming days, or will the limited and thoroughly difficult options the Obama administration talked about as it investigated, debated and analyzed how to confront the Bashar al-Assad regime be any less vexing to the Trump White House?

"Today's chemical attack in Syria against innocent people, including women and children, is reprehensible and cannot be ignored by the civilized world," said President Trump in a statement . "The United States stands with our allies across the globe to condemn this intolerable attack."

But beyond condemning the attack, what will he do? The Trump statement placed blame on the Obama White House, stating that these "heinous actions by the Bashar al-Assad regime are a consequence of the past administration's weakness and irresolution."

And therein lies the challenge: Trump himself tweeted on more than one occasion that attacking the Assad regime would have "no upside and tremendous downside." So has his thinking on Syria evolved? And if so, what option is America prepared to pursue?

White House spokesman Sean Spicer noted that "there is not a fundamental option of regime change" only days after US Ambassador to the United Nations Nikki Haley said at a news conference that "our priority is no longer to sit there and focus on getting Assad out."

The talk now from the White House is of exploring options and not "telegraphing" decisions as America holds "further discussions around the globe with our allies as far as the appropriate action." In other words, stay tuned.

Obama administration officials strongly disagree with the Trump White House's politicization of America's role in Syria's barbarism, but they do say that the world has for years let Assad attack his people with no checks or consequences in sight. And they say that the recent statements from the Trump White House shifting US policy from Assad must go to Assad is staying for now has helped build on the impunity the Syrian regime already felt.

"It is not shocking, it is predictable; that is what regime does, they just escalate when there is no response," says Wa'el Alzayat of the regime's chemical attack. Alzayat, former senior policy adviser to US Ambassador to the United Nations Samantha Power, helped lead the US effort to establish the joint investigative mechanism that sought to identify perpetrators of chemical weapons used inside Syria.

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He also advocated for greater US intervention in the Syrian conflict while serving in the Obama administration. "The regime has methodically tested the international community's resolve at every step of this conflict; it can be traced back to the early days of the revolution and its escalation of violence based on the lack of response from the international community. It began with bullets, then with mortars, then with shelling, then scuds and chemical weapons."

Says Alzayat, "This is not rocket science. Until or unless there is a credible deterrent, this will keep happening."

Alzayat's former colleagues at the State Department had argued for a negotiated settlement to the end of Syrian civil war, a war so blood-soaked it has run out of adjectives to describe its hell. And Secretary of State Rex Tillerson issued a statement repeating America's condemnation of the chemical weapons attack.

"It is clear that this is how Bashar al-Assad operates: with brutal, unabashed barbarism," Tillerson said. "It is also clear that this horrific conflict, now in its seventh year, demands a genuine ceasefire and the supporters of the armed combatants in the region need to ensure compliance. We call upon Russia and Iran, yet again, to exercise their influence over the Syrian regime and to guarantee that this sort of horrific attack never happens again. As the self-proclaimed guarantors to the ceasefire negotiated in Astana, Russia and Iran also bear great moral responsibility for these deaths."

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Yet even as America speaks out and pushes for an end to the civil war, the Trump administration is running into all the policy limitations that faced its predecessor. Whether it deals with them differently is not yet known. What is clear is that the already limited options facing the Obama administration have only narrowed in the months since Trump took office and that, for America, the ISIS fight continues to take priority, as it did under Obama.

So while the international community talks about and works for a deal to end the civil war, the heart-shattering battle wages on. And if things proceed as Alzayat and others fear, the world must get ready to look on at even more horror in the meantime.

No matter how strong the words from the international community today, they won't help toddlers survive the next chemical attack to rain down on their neighborhood unless they lead to a real and lasting end to Syria's war.