On Tuesday, President Barack Obama awarded the nation’s highest military decoration to Army Sgt. Salvatore Giunta for heroism in Korengal, which became a powerful symbol of the brutality and frustrations of the Afghan war. Giunta, the first living Medal of Honor winner of the Afghanistan and Iraq wars, braved heavy gunfire to pull a fellow soldier to cover and rescued another who was being dragged away by insurgents.

"Repeatedly and without hesitation, you charged forward through extreme enemy fire, embodying the warrior ethos that says, ‘I will never leave a fallen comrade,’" Obama said. "Your actions disrupted a devastating ambush before it could claim more lives. Your courage prevented the capture of an American soldier and brought that soldier back to his family."

The White House ceremony was a celebration of personal valor. But it also cast a brief spotlight on a setback of the war, now in its tenth year, at a time when the U.S. is eager to show progress in the increasingly unpopular conflict.

The perilous Korengal is in many ways a symbol of the limits of American power in Afghanistan and of the evolving strategy there. U.S. troops pulled out of Korengal and other remote, thinly populated areas in April when commanders decided it was better to use forces to protect civilian population centers. That strategy seemed more viable than keeping troops in scattered isolated outposts where troops were highly exposed to attacks from Taliban, al-Qaida and other foreign fighters.

But the move raised questions about the strategy of a war which was long under-resourced and whose focus has shifted from crushing al-Qaida to shoring up a fragile Afghan government.

If the valley was so strategic, why was it ultimately abandoned at the cost of so many lives? If defeating al-Qaida remains a goal, why pull back from an area used by the terror movement to slip in and out of its Pakistani sanctuaries?

At the White House, Obama reiterated the U.S. mission in Afghanistan: "To deny safe haven for terrorists who would attack our country, to break the back of the Taliban insurgency, to build the Afghans’ capacity to defend themselves."

The U.S. entered Afghanistan after the Sept. 11, 2001 attacks because the Taliban were giving sanctuary to al-Qaida fighters who orchestrated the attacks on the U.S. Now the mission has expanded to turning back a resurgent Taliban, improving governance, fighting government corruption and bolstering development — all goals that make assessing progress in the war more difficult.

The Korengal valley runs for 6-miles (10 kilometers) between two mountain ridges in Kunar province of eastern Afghanistan, a key route for al-Qaida to move in money, fighters and resources from Pakistan.

U.S. troops were trying to not only fight insurgents in Korengal, but to convince residents that they should support the Afghan government. But tribes in Korengal, who speak a distinct version of the Pashtu language, fiercely reject any outside interference, whether from Kabul or al-Qaida. Kunar, in general, has a long reputation of hostility to domination by outsiders — be they Soviet soldiers in the 1980s or Americans a generation later.

Al-Qaida was able to exploit the hostility generated by the presence of foreign forces.

Insurgents ambushed a team of Navy Seals in June 2005, killing three of them and then shooting down a helicopter sent to rescue the team. Sixteen more Americans died. The years that followed saw continual battles, small-scale but brutal, waged along the valley’s steep slopes and rocky ridgelines with ground fighting and airstrikes.

Sending in more troops likely wouldn’t have helped, the Washington-based Institute for the Study of the War concluded in a study published this summer.

"In some of the interior valleys such as the Korengal, it is not certain that an increase in manpower would equate to success, as the population remains distrustful of and even hostile to outsiders," it said.

Despite the pullout in April, U.S. troops still man a combat outpost at the mouth of the Korengal Valley. A month ago, U.S. and Afghan troops began offensive operations to rout insurgents from hideouts in Pech River Valley to the north.

Giunta, who completed two combat tours in Afghanistan totaling 27 months, was a serving as a rifle team leader on Oct. 25, 2007 when his squad was ambushed in the valley, under a full moon, by a well-armed, well-coordinated insurgent force.

"It was an ambush so close that the cracks of the guns and the whizzes of the bullets were simultaneous," Obama said recounting the fighting. "Tracer fire hammered the ridge at hundreds of rounds per minute — more, Sal said later, than the stars in the sky."

The two lead men in his squad were hit by enemy fire. A third was struck in the helmet and fell to the ground.

"Sal charged headlong into the wall of bullets to pull him to safety behind what little cover there was," Obama said. "As he did, Sal was hit twice, one round slamming into his body armor, the other shattering a weapon slung across his back. They were pinned down."

Two wounded Americans still lay up ahead. Giunta and his comrades regrouped and threw grenades, using the explosions as cover to charge ahead.

One of the wounded soldiers had been shot twice in the leg. As someone tended his wounds, Giunta sprinted forward under enemy fire to the crest of a hill.

"There he saw a chilling sight: the silhouettes of two insurgents carrying the other wounded American away," Obama said. "Sal never broke stride. He leapt forward. He took aim. He killed one of the insurgents and wounded the other, who ran off."

For the next half hour, Giunta worked to stop his friend’s bleeding and help him breathing until the wounded could be airlifted from the ridge.

With the battle over, Obama said, "they continued their mission."