On Saturday morning, Secretary of State John Kerry telephoned the parents of a 25-year-old Foreign Service officer who had been so uncommonly upbeat and manifestly idealistic amid pervasive gloom and cynicism when she helped coordinate his visit to Afghanistan two weeks before.

Anne Smedinghoff had seemed to embody the spirit of America at its very best, and she had been determined to venture out and demonstrate a greatness of heart even as our military withdrawal was making that continually more dangerous.

Kerry was now calling to tell Tom and Mary Beth Smedinghoff that their brave and buoyant daughter had been killed by a bomb-laden vehicle while she was riding in a convoy to deliver donated schoolbooks in Zabul province.

Her father would later tell reporters that Kerry “spoke glowingly of the work she’s been doing. He spoke very highly of her.”

“It was very good to hear,” Tom Smedinghoff added, embracing the affirming, as his daughter no doubt would have.

The father said Anne herself had called the house on Easter Sunday. She had spoken of meeting Kerry, and she had seemed as sunnily optimistic as ever.

“She sounded so upbeat and so positive and so excited,” the father told reporters.

She clearly had chosen exactly the right path when she took the Foreign Service test after graduating from Johns Hopkins University in 2009. She had been offered a number of career tracks and had chosen to become a public diplomacy officer, whose primary duty is, as defined by the State Department, to “explain American values and policies.”

Her first posting had been in Venezuela. Some of her colleagues there favored the security of remaining in the embassy, but she loved to venture out into Caracas, meeting the people and spreading her particular kind of Americanism. She represented her country by being warm and helpful and compassionate, and making people only happy she was there.

She had then become one of those rare souls to volunteer for a posting that was the ultimate challenge for an optimist, Afghanistan. The danger was exponentially greater in Kabul and growing greater still, but she was if anything more eager to journey beyond the embassy walls.

“She particularly enjoyed the opportunity to work directly with the Afghan people and was always looking for opportunities to reach out and help to make a difference in the lives of those living in a country ravaged by war,” her parents later said in a statement to the press.

Her official title was assistant information officer, but she also made herself a major booster of everything from the young Afghan who was nominated for an Oscar after his first attempt at acting to the Afghan women’s soccer team, some of whose members had in earlier years been able to play only in secret or by pretending to be boys.

Four months before she helped coordinate Kerry’s visit, Smedinghoff helped coordinate a visit by U.S. soccer team member Lorrie Fair, who held a clinic for her Afghan counterparts. Smedinghoff sought to make herself more credible by brushing up on her own footwork after-hours.

In the meantime, she chose for the cover photo on her Facebook page a picture of a road lined festively with Afghan flags.

“When do you get baaaack?” a Facebook friend asked.

“End of July,” she posted, adding that she was scheduled to undergo additional training right after Labor Day. “So I’ve got 1 month for shenanigans.”

She also posted on Facebook a truly remarkable photo from a war that had begun back when she was just starting high school. The photo showed her sitting in a helmet and body armor aboard a helicopter with two weary-looking American soldiers and an Afghan soldier who seems lost in his own country. They make her face appear only fresher, her smile only brighter.

“Helicoptering around Helmand,” the caption reads.

The image recalls to mind another young American woman who helicoptered among soldiers—the CIA operative whose role in tracking down Osama bin Laden was dramatized in the movie Zero Dark Thirty. Smedinghoff was a hero of another kind and certainly no less courageous.

On Saturday morning, Smedinghoff joined a convoy bound for the official opening of a new school in Qalot, the capital of Zabul province. A suicide car bomber killed her, along with four other Americans, identified in the immediate aftermath only as three soldiers and a civilian Defense Department employee.

The news soon reached Kerry, and he said he would make the call to Smedinghoff’s parents. She had clearly made a particular impression on the former Massachusetts senator, who had fought in another war that had proved unwinnable and was therefore able to appreciate better than most how remarkable it was for her to insist on demonstrating what was best in us even as we withdrew. He had returned from Vietnam to become an anti-war activist and famously asked a congressional committee, “How do you ask a man to be the last man to die for a mistake?”

A half-century later, Kerry was our new secretary of State, and he found himself notifying the family of the first Foreign Service officer on his watch to die trying to undo a mistake. Smedinghoff perished while attempting with books what we had been unable to accomplish with bullets.

“A brave American was determined to brighten the light of learning through books written in the native tongue of students that she had never met, but whom she felt compelled to help,” Kerry told the press. “She was met by cowardly terrorists determined to bring darkness and death to total strangers.”

On Monday, her remains were flown in to Dover Air Force Base in Delaware. Her parents were present when her coffin was carried off the plane with honors befitting a true American.

“We are consoled knowing that she was doing what she loved, and that she was serving her country by helping to make a positive difference in the world,” her parents said.

Her father offered the secret of that rare and memorable smile.

“She really felt she was making a difference.”