The challenge of sustaining that commitment should not be underestimated. As of early July, the United Nations estimated that more than 5.6 million Ukrainian refugees had been recorded across Europe. Millions more are displaced inside Ukraine, a devastating toll. Depending on the course of the war — unpredictable but still likely to last many more months, at a minimum — the migrant outflow may continue or accelerate. As Ukrainian cities are captured or rendered uninhabitable by Russian attacks, more migrants could seek refuge farther afield, in Britain, Canada and the United States

As in this country, Canada and Britain have established sponsorship programs, among other methods of entry, under which Ukrainians are resettled in homes. Under the U.S. version of that arrangement, called Uniting for Ukraine, roughly 30,000 migrants have been resettled, and another 30,000 or so have been approved for travel. Applications from would-be sponsors continue to roll in at a brisk pace; many are Ukrainian Americans around New York and Chicago. In Britain and Canada, too, tens of thousands more migrants are expected in the coming months.

U.S. resolve must continue unabated, and it should also grow to include refugees who lack sponsors. How the Biden administration meets this test will be an ongoing barometer of its commitment to American values and traditions.