The way Donald Trump and some other Republican presidential wannabes are talking, you’d think there are hordes of immigrants at our borders — even the one with Canada — about to overrun the United States.

What poppycock. If they want to see a real border crisis, it’s happening now in Europe, and it’s getting worse by the day.

Governments there face a monumental logistical and moral challenge, quite literally a matter of life and death. Almost daily, migrants drown in the Mediterranean — a death toll nearing 3,000 this year.

So far, however, Europe’s leaders are failing this test. On Friday, the United Nations refugee chief called on them to mobilize the continent’s “full force” in tackling the crisis.

It is the largest mass migration to the continent since the end of World War II — more than 350,000 and counting so far this year, a third of them women and children.

And who can blame them? While some are seeking a better economic life, many are refugees trying to escape war in Syria, Iraq and Afghanistan, or violence and persecution in Libya, Somalia and elsewhere in Africa.

The longer-term solution is to improve conditions on the ground so refugees don’t have to flee for their lives. In this larger effort, America can and should be a much better partner to our European allies. The Obama administration has been strangely, and shamefully, quiet on this crisis.

America can lead diplomatic efforts to end, or at least limit, the fighting, especially in Syria. As some U.S. senators are calling for, we can take in far more Syrian refugees than the 1,500 since the conflict began in 2011. We also can join Europe in offering far more humanitarian aid to Jordan, Lebanon and Turkey — countries that are way stations on primary migration routes.

Countries on the front lines — Greece, Hungary and Italy — are getting overwhelmed. Hungary’s nationalist government reacted by hurriedly putting up a razor-wire fence on its border with Serbia, and blocking migrants from boarding westbound trains. On Friday, thousands began walking toward Germany instead.

Last week, Chancellor Angela Merkel of Germany — which, along with Sweden, has taken in the most asylum seekers — finally showed some leadership. She urged all countries to more fairly share the burden, and warned if that doesn’t happen, some of the 26 European countries that allow free passage might once again impose passport checks at their borders.

“If Europe fails on the question of refugees, if this close link with universal civil rights is broken, then it won’t be the Europe we wished for,” she said.

She’s right about the enormity of what’s at stake.

Too many migrants are being greeted by riot police and being mistreated in makeshift camps. Gangs and human smugglers are preying on the vulnerable. Demagogues are having a field day. The time for coming up with a workable and humane plan is running out, fast.

That should have been proved with the shocking Aug. 27 discovery of 71 decomposing bodies in a truck abandoned on an Austrian highway. If that wasn’t chilling enough, approximately a dozen Syrians washed up Wednesday on a Turkish beach. A heartbreaking photo of a dead toddler face-down in the surf caused a worldwide outcry.

That image should be seared into the nightmares of European and American leaders until they confront this crisis head-on.

Editorial by the Sacramento Bee.