The following script is from "Ending America's Longest War" which aired on Jan. 4, 2015. Lara Logan is the correspondent. Max McClellan and Jeff Newton, producers.
Navigating the end of the longest war in American history is the job of General John Campbell, the last four-star general of the war.
His mission is making sure that after the U.S. withdraws from Afghanistan, the Afghan Security Forces do not go the way of Iraq where territory that was fought over and won by the U.S. at great cost was lost because the Iraqi military wasn't strong enough to hold the enemy back.
Could the same thing happen in Afghanistan? The U.S. combat mission officially ended on December 31st, but in a sign the Afghans need more time, the U.S. agreed to still play a limited role on the battlefield. Under Gen. Campbell's command, American forces will fly combat operations for Afghan troops when needed and U.S. Special Operations Forces will continue to hunt down al Qaeda with their Afghan counterparts. But, after 13 years of fighting, the war as Americans have known it is over.
America's longest war is being reduced to dust and rubble. You can see it here at Bagram Airfield...half the base is gone. Barracks, where soldiers slept, torn down. Bunkers bulldozed into piles of sandbags.
Equipment and vehicles shipped out at a relentless pace and close to 300 U.S. bases shut down to meet the deadlines set by President Obama. Much of what is left now belongs to the Afghans.
Gen. John Campbell: We've been at this for 13 years, been a lot of blood, sweat, tears. But I've seen some good progress, as well.
57-year-old John Campbell is one of the youngest four-star generals in the Army and this is his third tour in Afghanistan.
To show us what billions of dollars in foreign aid has done to make Kabul more modern, he flew us over the city just hours after we arrived. This was among the darkest capitals in the world when the U.S. got here. Now, the ancient city is ablaze with light.
Gen. John Campbell: This is a perspective people don't get. Kabul at night here. The lights.
Lara Logan: When I came into Kabul for the first time with the Afghan forces, when they took the city from the Taliban in 2001, there wasn't a single light--
Gen. John Campbell: Just take a look at the highway lights.
"We've been at this for 13 years, been a lot of blood, sweat, tears. But I've seen some good progress, as well."
But millions of people across Afghanistan are still without power and the lack of security threatens whatever progress has been made.
Last year was the deadliest of the war: more than 5,000 Afghan soldiers and policemen killed.
At this memorial down south in Kandahar, Gen. Campbell paid tribute to some of their fallen. Afghan Major General Abdul Hamid was at his side. He lost close to 200 of his men this past year.
Lara Logan: You believe that the Afghan security forces, particularly the Afghan National Army, doesn't get the credit it deserves.
Gen. John Campbell: It's the number one respected institution in Afghanistan. Couple years ago, I probably wouldn't have said that, but today it is. They've taken this fight on, they've gotten 'em through two very, very tough fighting seasons and the last one predominantly all on their own.
Lara Logan: The Afghan government can't afford to pay for them. The Afghan army, the police, the air force, they're all paid for by the U.S. and its allies. Casualty rates -- they're dying in huge numbers. Unsustainable, according to your deputy. The attrition rate's another area of concern.
Gen. John Campbell: Yeah, I mean, there's challenges. They know that the army they have today probably will not be the size several years from now. They just can't afford that. The casualties you brought up, you have to take a look and put that in context. So, in fighting season 14, their operational tempo was at least four times greater so you expect probably casualties to go up a little bit.
Leading the fight...Afghanistan's elite Special Operations units. The Defense Department released this video, which shows Afghan commandos on a nighttime clearing operation. At the height of the fighting season this past summer, they carried out over 150 missions every month. Eight years ago, these forces didn't exist.
Gen. Campbell flew us out to their main training facility in the high desert on the southern edge of Kabul, where they allowed us a rare opportunity to see some of these soldiers up close.
They have their own wing of specialized pilots and on this training exercise, the Afghan commandos showed how they would assault an enemy compound. While they operate mostly on their own, they still rely heavily on the U.S. in areas like intelligence and logistics. And there are fears over what will happen when the Americans withdraw, heightened by the collapse of U.S. trained forces in Iraq.
Gen. John Campbell: There is a lot more talk, from many of the senior leaders I deal with on the Afghan Security Forces, about Iraq and Syria and what's going on, and saying, "Hey, the coalition left Iraq, and a couple years later, look what happened. Don't let that happen to us here in Afghanistan."
Lara Logan: The U.S. significantly underestimated the risks of withdrawing completely from Iraq. Do you face any of the same risks here?
Gen. John Campbell: The fundamental difference is that the senior leadership, both on the military side and in the government, want the coalition. They want the U.S. to stay here.
Lara Logan: But do we share any of the same risks?
Gen. John Campbell: There'll still continue to be threats here in Afghanistan that will try to dictate that is it not stable. So absolutely.
Gen. Campbell has to weigh those risks against his orders to end this war for Americans. Here, he was pinning medals on some of the soldiers he was sending home. Under President Obama's mandate, U.S. troops are now down to about 10,000. There'll be half of that in a year. And, in December 2016, the U.S. mission is supposed to be over.
Lara Logan: You're operating on the president's timeline here. How much wiggle room do you have?
Gen. John Campbell: As any commander gets on the ground, he has to make an assessment and then provide his best military advice with senior leadership. So I'm constantly making those assessments.
Lara Logan: So you don't feel boxed in?
Gen. John Campbell: Well, I-- I feel like-- you know, I'm a four-star general, I'm not sure what you mean by "boxed in." If it means boxed in on the number of people I can have here and the timeline I'm on, again, if the administration just wanted somebody to come here and say, "Hey, you're not gonna make any changes, you're gonna do X," then they wouldn't need a leader that had the experience. They wouldn't have picked me.
President Ashraf Ghani: Deadlines concentrate the mind. But deadlines should not be dogmas.
Ashraf Ghani is the new president of Afghanistan, a former World Bank official who has spent much of his life in the U.S.
Pres. Ashraf Ghani: If both parties, or, in this case, multiple partners, have done their best to achieve the objectives and progress is very real, then there should be willingness to reexamine a deadline.
Lara Logan: Did you tell President Obama that?
Pres. Ashraf Ghani: President Obama knows me. We don't need to tell each other.
It took a firm hand from the U.S. to get President Ghani and his chief political rival, Dr. Abdullah Abdullah to share power, after a bitter dispute over fraud in the presidential election. It's Gen. Campbell's job to stay close to both men. He's now invited to attend their National Security Council meetings here in the palace, and says the new government is on the offensive. In our interview, President Ghani had strong words for the nation's enemies.
"If both parties, or, in this case, multiple partners, have done their best to achieve the objectives and progress is very real, then there should be willingness to reexamine a deadline."
Pres. Ashraf Ghani: Do not ever threaten an Afghan with violence. We will rise as one and we will face every threat the way we have taken on thousands of previous armies and conquerors. This is the moment of destiny. Work with us to transform Asia but should you threaten our existence everybody will be destroyed, not just us.
Lara Logan: You say that with a smile at the end.
Pres. Ashraf Ghani: Well, because I want to make sure people understand who they are dealing with.
Lara Logan: Who are they dealing--
Pres. Ashraf Ghani: The bones--
Lara Logan: --with?
Pres. Ashraf Ghani: --of my ancestor guide us. This country was not the gift of anyone. It is the results of millions of people sacrificing. What did we have? Our bare hands.
One of President's Ghani's biggest challenges is something John Campbell has dealt with before. When we first visited him here four and a half years ago, he was in charge of eastern Afghanistan, which borders Pakistan. During that visit in 2010, we were caught in an ambush with his troops along the frontier - a routine event for U.S. soldiers who faced the impossible task of fighting an enemy that flowed freely from its safe havens in Pakistan.
Lara Logan: We've had this conversation before, 2010, when you were division commander.
Gen. John Campbell: Three hours you made me talk about Pakistan.
Lara Logan: And nothing has changed on the battlefield. In fact, the Pentagon, in their most recent report on Afghanistan, said that-- "The resiliency of the Afghan insurgency continues to depend on sanctuary in Pakistan."
Gen. John Campbell: Well, everybody's been frustrated with Pakistan. Afghanistan has been frustrated. Pakistanis have been frustrated with Afghanistan. But I've seen change here just in the last couple of weeks with engagement with the senior leadership--
Lara Logan: Let's look at what hasn't changed in 13 years. The Pentagon, in their most recent report, said that Pakistan is continuing to provide sanctuary to America's most lethal enemies in Afghanistan, the Haqqani Network, which they describe as the most potent strain of the insurgency, the greatest risk to U.S. and coalition forces.
Gen. John Campbell: Yeah, I agree with you. Haqqani you brought up. They've been the greatest threat to the coalition. I've lost many soldiers because of Haqqani members. Am I frustrated because they come in Afghanistan, they go into Pakistan. Of course I am.
Lara Logan: The Pakistanis protect their leadership. They allow them to recruit. They allow them to rest.
Gen. John Campbell: I agree. You know, I'm not gonna tell you that I'm a friend of Haqqani here and that Pakistan is not providing them sanctuary. They are. We've known that for years.
Pres. Ashraf Ghani: We'll either sink together or swim together. We've both become mutually vulnerable and we both need to understand that stability in one isn't conceivable without the stability in the other.
Lara Logan: Can you understand the skepticism, though, given Pakistan's actions here?
Pres. Ashraf Ghani: Skepticism is part of your job. The job of an elected president is to overcome the past and change the playing field. My people are bleeding. It is precisely because of that that I need to make sure that peace comes.
But in remote parts of the country, like these mountains in Kunar Province, President Ghani's enemies are entrenched. We asked a local journalist to meet up with the Taliban fighters there. The U.S. ceded this ground to them when American soldiers were pulled out of here. This man, who goes by the name, Qari Abdullah, claimed to command 150 Taliban fighters.
He said: "We will fight against democracy wherever it is."
And he used this interview as an opportunity to pledge support for the Islamic State, which has threatened to move into Afghanistan.
"May we be united to spread our ideology throughout the world," he said.
Lara Logan: Are you concerned about the rise of the Islamic State and what threat that could pose here?
Pres. Ashraf Ghani: Yes. Yes. Because the past has shown us that threats, that networks change their form.
Lara Logan: But their ideology hasn't changed.
Pres. Ashraf Ghani: Their ideology gets more radical.
Lara Logan: How concerned are you about that threat?
Gen. John Campbell: There have been incidents of recruiting, of night letter drops that talked about different parts of the country. So they're concerned-- if they're concerned, I'm concerned about that. But I think with the military they have here, with the conditions that are set-- this-- again, this is not Iraq. I don't see ISIS, ISIL, coming into Afghanistan like they did into Iraq. The Afghan Security Forces would not allow that.
As Gen. Campbell transforms America's mission, there's no peace agreement with the enemy, no decisive military victory and no end to the war in sight. His challenge is making sure the soldiers he brings home do not have to go back.
Lara Logan: The U.S. came to Afghanistan after 9/11 to defeat al Qaeda. Thirteen years later, as the U.S. leaves, al Qaeda is still here.
Gen. John Campbell: What's the question?
Lara Logan: That's the question.
Gen. John Campbell: Are they still here? Are there small pockets? Are there leadership that we continue to go after and a network that supports them? Of course. Are they at a level that they can continue to attack and plan for the United States? We're doing everything we can today to make sure they don't have that capacity. But I think we're gonna have to keep continued pressure on that. Once you take that pressure off, it's only a matter of time before they continue to build that back up. So that's why it's so important that we do build upon the Afghan capacity to keep that pressure on. If we get to a point where I think their capability can't do that and they're still a threat to the United States, then I'll make sure my senior leadership understands that.