In September 2014, Pete Buttigieg left Kabul after a seven-month deployment.

The South Bend mayor said that, at the time, he figured he would be one of the last U.S. troops to Afghanistan. Five years later, however, Buttigieg is running for president while nearly 14,000 American troops remain in the country. "We need to wrap this up quickly," he told CBS News about the conflict there, which has now eclipsed Vietnam as the longest war in U.S. history.

"The one thing that everybody should be able to agree on, Democrats, Republicans, the Afghan government, the Taliban, the international community, and me is that we are leaving," Buttigieg said.

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As the American war in Afghanistan approaches its 18th anniversary next month, Buttigieg wonders "are we going to leave well or are we going to leave poorly," saying he "fears" that the current approach is one that is "driven by the American political calendar."

The Trump administration is in the middle of ongoing peace negotiations with the Taliban, at the center of which is a debate on how many of the nearly 14,000 troops will leave the five American bases in Afghanistan. Last week, President Trump told reporters "we are going down to 8,600." And on Monday, U.S. Special Representative Zalmay Khalizad told an Afghan news network that an agreement in principle has been reached to withdraw 5,000 U.S troops.

Tuesday afternoon, a Pentagon official confirmed to CBS News that the U.S will go down to the 8,600 troops in 135 days as a part of a deal signed with the Taliban. The White House has not yet confirmed details of the arrangement and the agreement is not final until Mr. Trump signs off on it.

Buttigieg said he wants to draw down to the "minimum required residual force." And to him, that means having a "highly limited" force with "special operations or intelligence capability like we might have in any number of places around the world."

The 2020 presidential candidate said the purpose should be "making sure that the American homeland is protected," adding, "beyond that, we really need the Afghan government to stand on their two feet."

South Bend, Indiana Mayor serves with the Navy Reserves in Afghanistan in 2014. Buttigieg's presidential campaign

The peace talks between the Trump administration and Taliban representatives have so far excluded the Afghan government. An agreement could potentially lead to the Taliban, a group that has committed numerous human rights abuses and still controls vast swaths of the country, once again taking power in Kabul.

Buttigieg said "we should welcome" the Taliban to be a part of the Afghan government provided they are "willing to lay down their arms and participate in a pluralistic democratic government." But he cautioned that "we need to make sure they are serious."

"I think the reality is there needs to be leverage in order to make sure that they live up to their commitments," Buttigieg said, "but that leverage doesn't have to be provided by the U.S. alone."

In the long run, Buttigieg thinks Afghanistan "can be" a U.S. ally because of similar desired outcomes and aligned interests. But if the Taliban are part of the government in Kabul, Buttigieg would not want the U.S. to continue sharing intelligence.

"I would be very skeptical that we can trust the Taliban with sensitive intelligence," Buttigieg said. "It is mostly for counter terrorism that we engage in that region to begin with."

Buttigieg spent time in Afghanistan in 2009 as a civilian adviser helping with economic issues. Five years later, after he had been elected mayor, he was deployed as a naval intelligence officer working with a unit to disrupt financial cells of terrorist networks.

While recalling his time in Afghanistan, Buttigieg pondered the "consequences of history" and the "harm that has come from war" given the "different ways in which the country has been used and in many cases abused by geopolitics."

"What I saw was a people that are courageous and determined and energetic," Buttigieg said. He added, the situation in Afghanistan "is a reminder of what happens when you don't have a long term vision that accounts for the wellbeing of everybody."

Buttigieg's campaign also offers up a number of people who served with the mayor to talk about what it was like. Major Andrew Stevens, for example, was in Afghanistan around the same time as Buttigieg in 2014 and remembers meeting him at a Cigar Club in Kabul.

"My first impression was that he is obviously really bright and smart," Stevens said, "but at the same time he's humble and down to earth."

Stevens, who also convinced Buttigieg to join a fantasy football league as a way to pass time, described the mayor as "culturally aware," and talked about a time the two went off base to volunteer with a local orphanage.

It was during the holy month of Ramadan and the group spent a couple of hours playing with the boys and girls after delivering books and clothing. Stevens, who was fasting that day, said during the lunch hour "everyone else was eating."

Stevens said he wasn't sure if Buttigieg was also fasting but remembers that "he was at least conscious of that and did not eat in that situation."

Lieutenant Commander Charles Murray, who spent most of his 23-year military career in the Navy and was in the same Reserves unit with Buttigieg in Illinois described him as "straightforward" with a "very calm presence."

"He never got riled," Murray said, "but he also had a good sense of humor about things."

Murray said that he always votes for Republican or Libertarian candidates and disagrees with Buttigieg on a wide range of issues. But he's still considering voting for Buttigieg, saying that their political differences are "immaterial."

"There should be a certain amount of faith in the Commander-in-Chief of the United States," Murray said, adding that Buttigieg's "character" and "credibility" are what set him apart.

Buttigieg often cites his experience door knocking in Iowa for the 2008 Obama campaign as the inspiration for him to serve. He talks about young Americans — those barely old enough to vote, but willing to put their lives on the line in order to protect the nation — as what motivated him to join the Navy Reserves after stints at Harvard, Oxford and the corporate consulting firm McKinsey and Company.

Regardless of whether he wins the presidency, Buttigieg said he wants to retire in 2054, the year he would turn 72. And when he does, he insists that he'd like to go back to Afghanistan as a civilian.

"My hope is that by 2054 I will be able to visit Afghanistan as a tourist," Buttigieg said. "It is a hauntingly beautiful country with extraordinary people and we all have an interest in there being peace and stability in that place."