Late last fall, as Joe Biden prepared to take office and act on his promise to restore America’s global leadership, Samantha Power had something to say.

It was all well and good for Biden to declare “America is back.” But nothing would prove it more, after four years of Donald Trump, than a show of sheer American competence.

“The United States can reenter all the deals and international organizations it wants,” Power wrote in an article in late November for Foreign Affairs magazine, “but the biggest gains in influence will come by demonstrating its ability to deliver in many countries’ hour of greatest need.”

The coronavirus pandemic, she argued, provided just such an opening. By spearheading global vaccine distribution, the United States could beat China at the biggest soft-power contest in generations, regain its reputation as the world’s “indispensable” nation and, not incidentally in Power’s view, do good.

Months later, she finds herself in position to argue the case directly in the upper echelon of the administration and to act on it, as President Biden’s administrator of the U.S. Agency for International Development, with a seat on the National Security Council (NSC). Among many other things, the 10,000-strong organization has spent decades building health systems and promoting vaccine campaigns around the world.

In an interview last week on her second day in office, Power was reluctant to call the still-raging pandemic that has killed millions worldwide an opportunity. Instead, she spoke of the “urgency” of the moment and the “unleashing” of a downtrodden agency whose morale has steadily deflated along with its status as a leading instrument of U.S. foreign policy.

The prestige of both USAID and the United States, she said, will be “recalibrated” if the agency “is unleashed to design programs around getting vaccines into arms in countries where we’ve worked for generations, for 60 years.”

And who better to lead the charge than a self-described “pain in the ass,” whose criticism, as a journalist in the 1990s, of U.S. inaction in the face of genocide in the Balkans helped nudge President Bill Clinton toward a bombing campaign? Or whose Pulitzer Prize-winning book, “A Problem From Hell,” lambasted those who “turned away” from such tragedies when they had the power to act?

As resident do-gooder scold in the Obama administration, where she served on the NSC staff and as U.N. ambassador, Power traveled to West Africa to bring attention to the Ebola epidemic and promoted U.S. interventions in Libya, Syria and beyond.

Among her prized possessions, kept in a shoe box at the family home in Boston, is a stash of notes passed to her by Biden, then vice president, during White House crisis meetings when President Barack Obama visibly tired of her interventions. Her favorite, Power said, read, “Go Irish!,” a reference to their shared heritage and the land of her birth. Others reminded her that “this is why [Obama] wants you here.”

With the coronavirus, Power is pushing on a door that is already at least partially open. On his first full day in office, Biden signed National Security Memorandum #1, directing the State Department and USAID to develop a strategic plan to lead the world out of the pandemic and combat future global health threats.

But as he made beating the virus at home his top priority, Biden was slow to respond to angry global demands to share U.S. expertise and supplies. It was only in recent weeks that he sent large quantities of direct coronavirus assistance to India and others — with every pallet of aid carrying the USAID logo — and voiced support for suspending patent rights to allow others to produce U.S.-developed vaccines.

Critics, both within and outside the administration, charge that Biden still has no overall strategy to address the pandemic, with piecemeal initiatives and authorities spread across departments. The Senate Foreign Relations Committee has scheduled a hearing Wednesday on the administration’s international coronavirus response, with testimony from Gayle E. Smith, the Biden administration’s State Department-based coordinator on the issue, and Jeremy Konyndyk, director of USAID’s coronavirus task force.

Power sees a major part of her job as convincing Americans that helping others helps the United States. “As covid illustrates better than any contemporary threat,” she told the Senate Foreign Relations Committee during her March confirmation hearing, “the fate of the American people” is connected to progress in the rest of the world. “Health infrastructure, economic prosperity, the curbing of extremism and radicalization . . . development and diplomacy have to be resourced and priorities alongside our essential defense efforts.”

Some lawmakers sounded less than convinced. Sen. James E. Risch of Idaho, the committee’s senior Republican, was generally supportive of Power but seemed skeptical of her passion. USAID, he said, needed to be “led by someone who understands that aid is most effective when targeted toward clearly defined U.S. interests. . . . The United States shouldn’t even consider trying to solve the world’s problems.”

Sen. Rand Paul (R-Ky.), as he has with other Biden nominees who served in the Obama administration, caustically asked how the 2011 U.S. bombing of Libya, which Power argued for strenuously, constituted the “humanitarian” intervention it was called at the time.

“Was it successful?” he asked, noting that it led to a civil war, a flood of migrants and the rise of new streams of terrorism in North Africa. “Our interventions make things worse, not better.”

Power reverted to diplo-speak. The decision Obama made to stop a threatened slaughter of residents of the Libyan city of Benghazi by then-leader Moammar Gaddafi was “incredibly difficult,” she said. “Certainly the fallout in the wake of intervention, the centrifugal forces have been difficult to manage” and “hard” on the Libyan people.

Others on both sides of the political aisle asked how she would address additional urgent challenges — the factors that drive migrant multitudes from Latin America to the U.S. border, the systemic corruption that consumes so much humanitarian and development assistance, the rise of demagogues and the undermining of the rule of law.

The United States had already spent billions trying to turn Central America’s Northern Triangle countries — Guatemala, Honduras and El Salvador — into places where their own citizens want to stay, Sen. Rob Portman (R-Ohio) said, and “the results are not impressive.”

Power offered only mild pushback, noting that some of the Central America programs had actually shown results — improving conditions in those countries if not necessarily stemming migration — before they were cut back or canceled by the Trump administration.

Unleashing USAID

From its creation in the early 1960s, USAID has steadily lost influence within the government and control over its own agenda and budget. Primacy over development programs in areas such as labor, climate and even democracy promotion have shifted to other departments. Although a congressional effort in the 1990s to subsume the agency into the State Department failed, subsequent new assistance programs such as President George W. Bush’s AIDS relief plan and Millennium Challenge Corporation took over much of the spotlight and the money flow.

While frequently boasting about U.S. generosity, President Donald Trump repeatedly tried to cut foreign aid spending — traditionally less than 1 percent of the U.S. budget, much of it going directly to national security partners. His efforts were largely blocked by Congress.

While Power says she is committed to working closely with other departments, she hopes to use USAID’s dormant expertise, coupled with her own drive, to bring much of the responsibility and money for development back to the agency.

As China moves “rapidly, in a whole-of-government way, with big checkbooks” to supplant U.S. influence around the world, the United States has “a whole set of comparative advantages,” Power said in the interview. “We partner with civil society. We believe in a free and open Internet. We have a private sector that is really what so many of these communities most want to see investing on the ground.

“We don’t have a predatory model. . . . We’re not deforesting the countries and contributing to climate change. Empowering communities to take charge of their own destinies, that’s what people most want. So I think when USAID is unleashed to bring that expertise to bear, if we resource it adequately, as we step up particularly on covid . . . I think you could start to see a recalibration in terms of what the different agencies do and where some of these authorities lie.”

Having spent much of her professional life as an activist before entering government, Power said she is well aware of the differences. “There is no question that government is bureaucracy, and government presents challenges, and we are divided domestically in ways that impede . . . what we wish to do internationally. There’s a lot that stands in the way.

“I appreciate being in the room and having the chance to make my case to the president.”

But she clearly sees her current job as a chance to directly combine her passion with policy. While she may have learned to temper the former in presenting her case to Congress or even the president, Power let it fly in her introductory speech to the USAID workforce.

“The truth is,” she told them, “I wanted to be one of you. When I decided to head off to the Balkans in my early 20s, I initially tried to find work as an aid worker in the hopes of directly attending to the suffering there. But sadly, I quickly realized I didn’t have the skills. I wasn’t an engineer or a health or agriculture specialist. . . . I had no technical expertise whatsoever.”

“So, I became a war correspondent.”

But the U.S. aid workers she encountered in the field, she said, showed they had both the determination and the expertise to change people’s lives, far beyond the emergency and natural disaster assistance to which USAID has become most closely identified in recent decades.

“You don’t shy away from the world’s pain,” Power told the workforce. “You don’t consider it someone else’s problem. You act, you serve, you draw on that grit, and you promote people’s dignity.

“For all the lofty pronouncements we can make about America’s global leadership, it is our country’s actions, our ambition, our ability to get big things done that truly moves minds and changes futures.”