Average Americans didn’t need a United Nations special report on poverty in the U.S. to learn that theirs has become a pyramidlike society of extreme wealth at the top and extreme poverty for millions at the bottom.

But a valuable new U.N. report that triggered outrage in the administration of President Donald Trump last month disclosed that 40 million Americans live in poverty, with 18 million in “extreme poverty.” It labeled the U.S. the most unequal country in the developed world — a humiliating label for a nation that also is the world’s richest and most powerful.

But the Trump administration’s outsized response, epitomized by the U.S. ambassador to the U.N., Nikki Haley, was deeply hypocritical. Haley publicly rebuked the organization, calling its report “misleading and politically motivated.” What she didn’t say is that the report drew its numbers from no less an authority than the U.S. Census Bureau.

And even those numbers don’t tell the full story of need in this country. Many Americans would feel poverty’s pinch long before they fell to the official level of $24,000 for a family of four — about $468 weekly. As a reminder of how hard it would be to make such a salary stretch to cover basic living expenses, the average two-bedroom apartment in the Twin Cities rents for more than $1,200.

The U.N. has long made it part of its mission to document conditions that can destabilize nations, whether they are extreme poverty, political oppression or disenfranchisement. In its latest report, the U.N. turned its spotlight on the U.S., documenting the vast numbers of Americans — many of them people of color but many more of them white — trapped in wages so low they cannot escape the ranks of the poor, no matter how many hours they work.

While state laws vary, the federal minimum wage in this nation is still $7.25 — a mere $15,000 a year even at 40 hours a week. Those toiling at such jobs often struggle with subpar housing and schools, all of which, the U.N. report noted, contribute to homelessness and other social ills.

Tellingly, deep poverty — those making less than half the federal poverty threshold — has been on the rise, according to the Center for Poverty Research at the University of California, Davis.

In his report, Philip Alston, the U.N.’s special rapporteur on extreme poverty and human rights, rightly acknowledges that there is no magic bullet for wiping out poverty. But he notes that this country’s great wealth confers on it a commensurate obligation to address its poor more effectively than has been the case. “In a rich country like the U.S., the persistence of extreme poverty is a political choice made by those in power,” he said. “With political will, it could readily be eliminated.”

Haley’s response was embarrassing in its arrogance. That the U.N. should have the temerity to examine poverty in the U.S. was “ridiculous,” she said, adding that its resources would be better focused on countries such as Burundi and the Democratic Republic of Congo. “The special rapporteur wasted the U.N.’s time and resources, deflecting attention from the world’s worst human rights abusers and focusing instead on the wealthiest and freest country in the world,” she said.

But Haley, still relatively new to international diplomacy, would do well to check her rhetoric and to remember that America leads best by example. Its message to the rest of the world cannot be “Do as I say, not as I do.” Alston, and by extension the U.N., recognize that the world needs the U.S. to continue as a stabilizing force in the world. From observing regimes round the world, they know all too well that widening economic inequality, a shrinking middle class and systems too heavily tilted toward the wealthy and powerful jeopardize that stability.

It takes a good friend to challenge you when you stray from long-held values — someone who can remind you of who you are. Such is the wake-up call, uncomfortable though it may be, that this nation has received from its partners at the U.N., an organization it helped create for the very purpose of spurring nations to reach higher and do better.