Leaders from around the world have descended on New York for United Nations meetings, fancy parties, ringing speeches about helping the poor — and a big dose of hypocrisy.

And — finally! — this is one area where President Donald Trump has shown global leadership.

If there were an award for United Nations chutzpah, the competition would be tough, but the medal might go to Trump for warning that if necessary, “we will have no choice but to totally destroy North Korea.” There were gasps in the hall: A forum for peace was used to threaten to annihilate a nation of 25 million people.

There also was Trump’s praise for American humanitarian aid to Yemen. Patting oneself on the back is often oafish, but in this case it was also offensive. Yemen needs aid because the U.S. is helping Saudi Arabia starve and bomb Yemeni civilians, creating what the U.N. says is the world’s largest humanitarian crisis. In other words, we are helping to create the very disaster that we’re boasting about alleviating.

It was also sad to see Trump repeatedly plug “sovereignty,” which tends to be the favored word of governments like Russia (even as it invades Ukraine and interferes in the U.S. election) and China (as it supports corrupt autocrats from Zimbabwe to Myanmar).

Meanwhile, world leaders usually ignore places that don’t fit their narratives. Everybody pretty much shrugged at South Sudan and Burundi, both teetering on the edge of genocide; at Congo, where we’re headed for civil strife as the president attempts to cling to power; and at the “four famines”: in Nigeria, Somalia, Yemen and South Sudan. To Trump’s credit, he expressed concern Wednesday about South Sudan and Congo and said he would dispatch U.N. Ambassador Nikki Haley to the region to see what can be done; let’s hope his administration provides desperately needed leadership.

In fairness, there are broader reasons for hope, including astonishing progress against global poverty — more than 100 million children’s lives saved since 1990.

For the first time in human history, less than 10 percent of the world’s population is living in extreme poverty, and we probably could virtually eliminate it over the next 15 years if it were a top global priority. Trump rightly hailed PEPFAR, the AIDS program President George W. Bush devised, but he also has proposed sharp cuts in its funding.

We now have the tools to achieve enormous progress against these common enemies of humanity — poverty, disease, slavery — but it’s not clear we have the will. What’s striking about this moment is that we have perhaps the worst refugee crisis in 70 years, overlapping with the worst food crisis in 70 years, overlapping with risks of genocide in several countries — and anemic global leadership.

And many countries are divided at home, distracted by political combat and looking increasingly inward, and in any case, the U.S. remains the indispensable superpower, and it is AWOL. .

The number that I always find most daunting is this: About one child in four on this planet is physically stunted from malnutrition. And while it is the physical stunting that we can measure, a side effect is a stunting of brain development, holding these children back, holding nations back, holding humanity back.

So it’s maddening to see world leaders posturing in the spotlight and patting themselves on the back while doing so little to tackle humanitarian crises that they themselves have helped create.