Obama leaned forward, smiling, and said, "My legacy will be determined by other things also." I answered without hesitation, "But Syria will be important, Mr. President."

I remembered the encounter as I read the "exit memo " Obama wrote to his fellow Americans. President Obama was looking back on the past eight years. Syria, one of the worst humanitarian disasters in our lifetime, was not mentioned. Obama touted carefully his successes in the economy, health care and Iran nuclear deal, among other things, while completely ignoring Syria.

As a physician and humanitarian who has spent the past six years helping in medical relief in Syria and neighboring countries, I saw the impact of Obama's policy, or lack of policy, on the ground. I saw it in the faces of countless helpless refugees in the Zaatari camp in Jordan and in the Greek camps during my medical missions. Among them was a child with a rare muscle disorder who was struggling to breathe in his hot tent in northern Greece. His family, like tens of thousands of desperate Syrians, took the perilous trip across the Mediterranean Sea to flee the brutality of war.

I saw it in the screaming of children as they were pulled from under the rubble of their destroyed houses. Among them was Abdullah, a 12-year-old victim of a barrel bomb in Aleppo. He suffered a traumatic injury to his chest, and we had to insert a chest tube to drain the blood without painkillers or anesthesia. He was screaming in pain.

Many areas in Syria were, and still are, under siege and daily bombardment, mostly by the Assad regime. There is a shortage of food and medicine.

I saw the impact through the desperate calls of my colleagues in other parts of Syria, struggling to resuscitate victims of nerve and chlorine gas attacks.

I saw it in the unprecedented "forced evacuation," a more gentle term for ethnic cleansing, of more than 250,000 people from their neighborhoods in Aleppo. Among them was Bana Alabed, 7, who (with her mother's help) tweeted to the outside world while she was under siege in her city.

The Syrian crisis has been an utter failure of Obama's foreign policy. Since the civil war's start in 2011, the United Nations estimates about 400,000 Syrians have been killed and nearly 12 million displaced. The crisis has created more than 4.8 million refugees.

How did Obama's policy fail? Early in 2011, and in response to the brutal clampdown on early peaceful demonstrations by Syrians, Obama stated that Assad had lost his "legitimacy." But he failed to support his statement with proactive policies to force an early political transition.

Words have power, especially if they are uttered by the leader of the free world. As Robert D. Kaplan  in The New York Times, "only if we project power can our values follow along." 

Syrians believed Obama's words. Thousands of them went to the streets demonstrating against the brutal Assad regime. They believed naively in the lofty ideals that Obama articulated, but they were very disappointed. The regime responded with extreme brutality, and the U.S. did too little to stop it.

Vladimir Putin, Iran and Assad called Obama's bluff and gained the upper hand, while the U.S. lost credibility and influence. The U.S. was not included in the last cease-fire talks among Russia, Turkey and Iran following the disaster of Aleppo.

Meanwhile, millions of Syrian refugees have been fleeing barrel bombs, chemical weapons and air strikes. The refugee crisis has destabilized the [European Union and given rise to anti-refugee sentiment, xenophobia and Islamophobia, which have contributed to the rise of extreme-right political parties across Europe.

President Obama refused to listen to his advisers, allies and critics. Among them were prominent Democratic and Republican leaders in Congress, leaders of allied countries and experts in foreign policy.

As he is trying to cement his legacy, Obama has been minimizing the deleterious consequences of his policies in Syria, while suggesting that he was successful by not being sucked into the quagmire of yet another crisis in the Middle East.

I doubt that history and the millions of Syrians who have lost everything will agree with his measure of success.

Dr. Zaher Sahloul is a critical-care specialist from Chicago, founder of the American relief Coalition for Syria and a volunteer in the Syrian American Medical Society.