The brutal separation of children from their parents at the U.S.-Mexico border is an abomination for which there is no morally acceptable justification. It is a practice that simply must stop.

Seeking to deter illegal entry into this country is one thing, but using helpless children as the deterrent is not something any civilized nation should find tolerable. It is a violation of human rights and, beyond its sheer cruelty, a practice that robs the U.S. of any moral high ground in dealing with other nations’ rights abuses.

That the practice has been extended not just to those caught crossing the border without legal documentation, but to asylum-seekers who are making a case for entry — in accordance with international conventions — is almost unthinkable. This nation has been a world leader in refugee resettlement, offering a haven to those fleeing war, persecution and violence in their homelands.

It has never been the case that all who seek are accepted. But neither has this country taken those seeking refuge and, instead, ripped their children from them, sending the parents off for prosecution and the children to far-off federal shelters. “Those seeking asylum are not breaking the law,” said John Keller, of the Immigrant Law Center of Minnesota. “They are following international standards that this country has agreed to. We need to dispel this doublespeak the administration is using. Under any normal administration, the U.S. would be condemning this practice, not initiating it.”

No one knows how many children have been taken. The government will confirm only that more than 10,000 migrant children are in federal custody in 14 states. A large number of those crossed the border as unaccompanied minors, but at least 700 have been forcibly separated from their parents since last fall. One in seven was under the age of 4. It is horrifying to think of the U.S. being the agent of such developmental and psychological trauma in children that young. Those unmoved by that prospect may want to consider the cost of feeding, clothing, sheltering and supervising these children in federal facilities.

Little wonder that the United Nations human rights office has condemned the practice as “a serious violation of the rights of the child” and called on the U.S. to immediately halt the separation of families. The U.S. is, as the U.N. points out, “the only country in the world not to have ratified the U.N. Convention on the Rights of the Child.” Embarrassingly, the U.S. ambassador to the U.N., Nikki Haley, engaged in “whataboutism” by pointing to the “reprehensible human rights records” of other nations, adding with a Trumpian flourish that no one, including the U.N., “will dictate how the United States upholds its borders.”

This practice and the ensuing condemnation by other nations is particularly painful in Minnesota, a state with a rich history of extending an open hand to refugees and asylum-seekers.

Perhaps most reprehensible is President Donald Trump’s refusal to take responsibility for his administration’s policies. “I don’t like the children being separated from their parents,” Trump said last week. “I don’t like it. I hate it.”

You can’t have it both ways, Mr. President. You have the power to stop this now. And you know — despite your assertions to the contrary — that there is no U.S. law that compels the separation of parents and their children at the border.

Democratic senators — including U.S. Sens. Amy Klobuchar and Tina Smith of Minnesota — have sent a letter asking for an end to family separation. Republican U.S. Rep. Erik Paulsen told an editorial writer that he is greatly concerned. “The U.S. has a reputation for accepting refugees. We don’t want to be in the position of forcibly breaking up families. That is just not what the U.S. is about.”

Indeed, it is not. But concerns must be followed by action, or the culpability for this tragedy in the making will extend to those who did nothing.