MEXICO CITY – First lady Michelle Obama stepped into a more prominent, more ambitious role on the world stage this week with visits to Haiti and Mexico. In each country, she had a single overarching message: Children can change the world. And as much as she can, she wants to make sure they have every opportunity to do so.

She delivered her most direct call to arms in Mexico City during a speech delivered before a shoulder-to-shoulder crowd of 3,000 young adults at the Universidad Iberoamericana – an elite Jesuit university. Obama quietly took nations, governments and societies to task for their failure to deliver on what she has described as the rights of all youth to be educated, nurtured and inspired.

“We must confront wrong and outdated ideas and assumptions that only certain young people deserve to be educated, that girls aren’t as capable as boys, that some young people are less worthy of opportunities because of their religion or disability or ethnicity or socioeconomic class. Because we have seen time and again that potential can be found in some of the most unlikely places,” she said.

“My husband and I are living proof of that.”

But in championing the rights of young people, she also reminded them that they owe a debt to their communities. And so under Wednesday afternoon’s sunny skies and with Mexico’s first lady, Margarita Zavala, looking on, Obama engaged in her own version of youth diplomacy. She challenged the world’s vast population of young people to make history themselves and to take ownership of some of the globe’s most daunting challenges.

“Soon, the world will be looking to your generation to make the discoveries and build the industries that will fuel our prosperity and ensure our well-being for decades to come. We’ll be looking to your generation to seize the promise of clean energy to power our economies and preserve our planet for your kids and grandkids,” she said. “We’ll be looking to your generation to find the courage and patience to resolve the conflicts and heal the divides that plague our world. And I’m here today because I believe that all of you – and your peers around the world – are more ready than ever to meet these challenges.”

Her audience, which read her speech as it was translated from English to Spanish on a large video screen, stood rapt. Save for the occasional chuckle when she tried out a few judiciously chosen Spanish phrases such as “Si se puede” (“Yes we can”), the audience was silent. No one interrupted her with applause. No one squirmed. No one stirred.

Obama chose the Mexican capital as the launching pad for an international agenda that she describes as “youth engagement,” partly because of its proximity to the United States, but also because of its cultural emphasis on family and faith, because nearly half of the Mexican population is under the age of 25, and because of the inextricable economic and cultural relationships between the two countries, she said.

One of the most pressing issues confronting the United States and Mexico is the drug trade, particularly the violence that has erupted along the border. Before Obama’s speech, the dean of the university, Jose Morales Orozco, addressed the concerns head-on in his opening remarks, calling the death and mayhem a “painful situation.”

And in private meetings with Zavala, both here and in Washington two months ago, Obama discussed drug addiction and treatment opportunities. But the first lady did not raise the topic in her public comments.

In an interview with reporters following her speech, she explained her omission, noting that as first lady, she’s focused on the “big picture,” not policy – that is for the president to do.

She wanted to use this trip “to remind us in the U.S. and our partners in Mexico that more connects us than the violence and the drugs,” she said.

“Our young people struggle with some of the same challenges. Drug violence exists on the South Side of Chicago, in L.A.,” Obama added. “You name any urban or rural environment and it’s there. And I think we all know we have to focus not just on curbing demand for drugs, and the cartels, but also on looking at expanding opportunities for young people.”

“If young people don’t have an alternative in their lives, they’re going to engage in drugs,” she said. “They’re going to choose the drug trade.”