South Bend, Indiana, Mayor Pete Buttigieg said during Tuesday’s Democratic debate that, if elected president, he’s committed to withdrawing all troops from Afghanistan by the end of his first year in office.

The 2020 Democratic candidate, who did a seven-month tour in Afghanistan as a naval officer, made the promise during the first night of this week’s Democratic primary debates in response to a question from CNN’s Jake Tapper.

Tapper mentioned the two US service members who were killed in Afghanistan this week — making that 14 deaths in 2019, the 18th year of the war. “You said one thing everybody can agree on is we’re getting out of Afghanistan. Will you withdraw all US service members by the end of your first year in office?” Tapper said.

“We will withdraw,” Buttigieg responded. “We have to.”

Tapper pressed him again if that meant in his first year. Buttigieg said yes.

“Around the world, we will do whatever it takes to keep America safe,” he continued. “I thought I was one of the last troops leaving Afghanistan. I thought I was turning out the lights years ago.”

Buttigieg also pointed out that “we’re close to the day” when America will get news of the death of a US service member in Afghanistan who wasn’t even alive on 9/11, the attack that prompted the US to invade the country in the first place.

His commitment on the debate stage is a big one. Three presidents have overseen the war in Afghanistan. Barack Obama was unable to end the war, and Donald Trump, who promised to reduce America’s commitments overseas, has also kept troops there.

Buttigieg, like other Democratic candidates, has discussed ending America’s “forever wars.” He has also previously vowed to “repeal and replace” the Authorization for Use of Military Force (AUMF), which allowed the president to use all “necessary and appropriate” force against those organizations responsible for the 9/11 attacks.

Though this largely meant going after al-Qaeda, the AUMF gave the president broad authority to go after terrorism anywhere, including in Syria and some regions of Africa.

Buttigieg said during the debate that any future AUMF should include a three-year sunset clause that must be renewed if engagement is to continue. “If men and women in the military have the courage to serve, members of Congress have the courage to vote.”

Other Democratic primary candidates, including Sen. Kirsten Gillibrand (D-NY), have suggested repealing and potentially replacing the AUMF, including by adding time limits. And candidates such as Sen. Bernie Sanders (I-VT) have criticized America’s “forever wars.”

But on the debate stage, Buttigieg offered a definitive and ambitious timeline — a sound bite that will be played over and over again if he gets close to the Democratic nomination or becomes president. That the only person to make such a commitment is also the only person on the debate stage Tuesday to have served in the US military is likely no coincidence.

Former Texas Rep. Beto O’Rourke, asked the same question in Tuesday’s debate, said he would commit to withdrawing troops by the end of his first term, but not necessarily by the first year. “There is nothing about the war in its 18th year that will make it better,” O’Rourke said. “We have satisfied the reasons for our involvement in Afghanistan in the first place. It’s time to bring the service members back home.”

The Council on Foreign Relations, in an article published ahead of the debates, asked 2020 Democratic candidates a slew of foreign policy questions, including whether they’d commit to removing US troops from Afghanistan by the end of their first term.

Few gave clear timelines, though Rep. Tim Ryan (D-OH), also committed to bringing troops home by the end of this first term. Sanders said he’d withdraw troops “as expeditiously as possible.” Sen. Cory Booker (D-NJ) also said he’d bring troops home “as soon as possible.”

Foreign policy didn’t get all that much attention in the latest debate, though it made an appearance toward the end, and there was some substantive discussion not just on Afghanistan but on North Korea and nuclear proliferation as well.

But Buttigieg’s first-year promise could change the discourse around the “endless wars,” giving candidates an ambitious road map to follow. Buttigieg, and Democrats writ large, may also be helped by an ongoing peace process in Afghanistan and the Trump administration’s plans to reduce troop deployment to the region in 2020.

Or maybe not. If America’s “endless wars” have taught us anything, it’s that they’re extraordinarily hard to end.