Then-Maj. Gen. Austin “Scott” Miller at Fort Benning, Ga., in 2015. On June 19, he testified before the Senate Armed Services Committee as a three-star general up for promotion to be President Trump’s next Afghan war commander. (Sgt. 1st Class Michael R. Noggle/Army)

The U.S. general nominated by President Trump to be the commander of the war in Afghanistan told the Senate Armed Services Committee on Tuesday that he wouldn’t speak about the war reaching a turning point “unless there is one.”

The statement by Army Lt. Gen. Austin “Scott” Miller during his confirmation hearing was an acknowledgment that the war has dragged on nearly 17 years and of how past U.S. commanders often proclaimed that conditions were set for forces to make significant progress soon.

Miller said that he couldn’t “guarantee you a timeline or an end date” but that the United States should stay in Afghanistan because it is vital to U.S. interests and countering terrorist groups.

“This is about protecting U.S. citizens, when you go right to the heart of the issue,” he posited.

Miller was nominated this spring by Trump to take over for Army Gen. John W. Nicholson Jr., who has led the war effort since March 2016. Miller has spent much of his career as a member of Special Operations Command, most recently as the commander of Joint Special Operations Command (JSOC), which includes the elite forces commonly known as SEAL Team 6 and Delta Force.

Miller testified 10 months after Trump announced a strategy change in Afghanistan that includes loosening the rules of engagement to allow more airstrikes, modestly increasing the number of U.S. troops to more than 15,000 and pointedly saying that the United States will not set a timeline for withdrawing unless conditions on the ground improve. The last point especially marked a change from the Obama administration, which deployed more than 100,000 U.S. troops to the country but pulled out more than 90 percent of them as security disintegrated.

Miller’s confirmation is considered a foregone conclusion, with numerous senators expressing admiration for his service during the hearing. At one point, Sen. Lindsey O. Graham (R-S.C.) asked him whether he had been wounded in the past, seemingly just to get the point on the record. Miller responded that he had been twice: during the 1993 Battle of Mogadishu — an operation recounted in the book and movie “Black Hawk Down” — and about 10 years later in Iraq.

But Miller did take tough questions from lawmakers concerned about whether success in Afghanistan can be achieved. Sen. Elizabeth Warren (D.-Mass.), in particular, said that even after 17 years of U.S. involvement, Afghanistan is “in crisis,” with Afghan military units suffering “unsustainable” losses, rampant corruption, about half of all children not in school and the Taliban increasing the amount of territory under its control.

“Even if U.S. forces could somehow stabilize the security situation, can we realistically expect a political settlement without addressing these underlying challenges?” she asked.

Miller responded that the military “supports the political,” and said that the political side continues to seek reconciliation with the Taliban.

“Some of those underlying challenges will have to be addressed,” he said.

Sen. Angus King (I-Maine) questioned how the United States can change the dynamics in Afghanistan if it could not do so when more than 100,000 troops were there under President Barack Obama.

“Nothing seems to change. What’s going to change in the next two years or three years?” King asked, adding that he did not think the situation was Miller’s fault.

Miller responded that the war has changed since the Obama-era surge because Afghan forces now lead the fight against militant groups “except where our vital national security interests are at risk,” an allusion to the U.S.-led counterterrorism mission. Previous Afghan war commanders have made similar points.

The general, asked what the largest challenge is in Afghanistan, said that it’s “the neighbors.” Under questioning, he said that the United States “ought to have high expectations” of Pakistan but did not elaborate on whether he thought that country has been helpful in the last year. Part of the strategy that Trump announced last year was getting tougher on Pakistan’s support for the Taliban, but the administration has done little since then to explain how it is doing so.