In each of those cases, the United States resettled far more refugees than any other country; and rightly so, given our direct involvement in the conflicts and our capacity to help. Thus far, the United States has provided more humanitarian funding than any other country. But of the 130,000 Syrians resettled in third countries after fleeing the conflict to one of Syria’s neighbors, the United States has accepted only about 18,000.

Turning away from our historical leadership on these issues provides no relief for those who need it most. Those people include a family of four Syrian refugees currently in Jordan that our organization is trying to help. The father is a survivor of torture; his two sons are of Syrian draft age and both suffer from extreme anxiety and seizures. They lived a simple lifestyle in Homs — the father was a shopkeeper — until the day their house was bombed, causing one of the sons to lose his hearing. Knowing Syria was no longer safe, they fled to Jordan in 2013.

The family had completed their resettlement interviews and medical checks, and were fully approved for refugee resettlement in the United States when President Trump signed his first executive order in January, putting their resettlement in limbo. Mr. Trump’s revised order places a 120-day freeze on all refugee admissions and slashes the overall refugee resettlement number to 50,000, from 110,000. Departures have ground almost to a halt. The family has no idea what is going to happen to them or where they can go, and they are extremely anxious about their future.

In a refugee crisis this large, resettlement to a third country is, of course, only one tool at the disposal of nations seeking to help — the vast majority of those people must be assisted where they are. But the Trump administration has demonstrated a similar disdain for other means of assistance, including by seeking to slash the budget for agencies like the State Department that administer it.

In declining to do more, Mr. Trump is violating a principle he has long championed — that the burden of addressing global challenges must be shared. Just as he has pressed NATO allies to spend more on defense, Chancellor Angela Merkel of Germany might well have been tempted, during her Oval Office meeting with Mr. Trump, to demand that he resettle some of the quarter million Syrian refugees currently applying for asylum in Germany.

The Trump administration has said, while presenting no evidence, that its draconian response to the crisis is justified by the threat refugees pose in the United States. Hundreds of national security experts from both parties and a series of federal court decisions disagree.

But no one, including, it now seems, Mr. Trump himself, disagrees about the human tragedy unfolding in Syria. Shocked by that reality, the president shifted his position on United States military action virtually overnight. Whatever one thinks of his decision, it was encouraging that Mr. Trump is capable of changing his views when confronted by compelling facts. If his newfound outrage is genuine, he should also reverse course on his unconscionable refugee policy.