ABC News / By MIKE BOETTCHER

As President Obama sets in motion a drawdown of U.S. troops from Afghanistan, military service members on the war's front lines shared poignant reflections on the milestone and offered a candid assessment of what it means.

Gen. Daniel Allyn, commander of the 1st Calvary Division, said fewer boots on the ground in Afghanistan in the years ahead won't shake the commitment of his soldiers to all that they've been fighting for.

"I have the opportunity of presenting Purple Hearts every night at Craig Hospital to the heroes who gave their all of this effort, and they are absolutely committed to accomplishing the mission," he said. "They are absolutely committed to their buddies, and they know that this matters and it matters for the future of Afghanistan."

Allyn added that he has confidence the Afghan Army, which will gradually take over the security mission from the U.S., feels the same way.

"The bottom line is [that] it's central to the future and, frankly, that's why the future looks very good," he said.

Allyn's deputy, Brig. Gen. Gary Volesky, put the milestone in personal terms.

"I've got a 13-year-old son back at home who has watched me go to Iraq three times and now he sees me in Afghanistan," he said.

"They haven't been attacked [in the United States] since 9/11," he added. "It means something right here to our nation because we're forward fighting the war on terror ... here."

The soldiers of the No Slack Battalion with the 101st Airborne, which has been assigned perhaps the toughest area of Afghanistan, Kunar Province, known as "The Heart of Darkness," told ABC News the costs of the war have been burdensome and painstaking. But from their vantage point, the mission has been a success.

"As with everything, it comes with a cost," said Capt. Ed Bankston. "And the thing I'll always remember is every one of my soldiers and how they performed, especially the ones I've lost."

"We're here to do one thing: We're here to win, and that's what we did, we won," said Sgt. Mendez, who did not want to give his first name. "It's going on a decade we've been fighting this war. ... I don't see us getting out of here anytime soon. But we are making a difference, we are taking it to the enemy now."

The spirit of perseverance amid sacrifice is a recurring theme among men on the front lines, news of a gradual withdrawal notwithstanding.

"The more time I spend out here and the more time I can go on missions and patrols to ensure that the future guys that are coming through aren't gonna get hurt, so be it, I'll do it," said Spc. Patrick Harper. "I'll do it every single day if I have to.

"I truly believe we're making progress here. I truly do. This place is a lot safer than it was when we got here," he said.

Cpl. Thomas Shelton said he believes making his corner of Afghanistan safer also means life will be safer in the U.S., thousands of miles away. He suggested that's what motivates him and his comrades to take the risks that they do when they go into battle.

"I've got a newborn son," he said.

"He's got a daughter that's about a year old," he added, referring to a fallen fellow soldier. "He sacrificed not only his life, he sacrificed that time with his daughter and bringing her up in this world. And he did that for you, he did that for me, he did that for his family back home so that the fight stays here, so that it does not come back to America."