According to administration officials, Pentagon official Ashton Carter is expected to be President Obama’s nominee to replace Chuck Hagel as U.S. defense secretary. (Reuters)

According to administration officials, Pentagon official Ashton Carter is expected to be President Obama’s nominee to replace Chuck Hagel as U.S. defense secretary. (Reuters)

President Obama may have picked a new defense secretary, but an older and thornier problem remains: The commander in chief, who publicly committed to ending America’s two wars, must find ways to inspire the men and women he continues to send into battle.

Obama has had a difficult relationship with the military and his defense secretaries, who have often questioned his passion and commitment to the military’s mission. Those misgivings could grow as troops, haunted by the

muddled outcomes in Iraq and Afghanistan, increasingly ask whether the past 12 years of war were worth it.

“The military and veterans look to the president to give them a story that justifies their sacrifice,” said Mike Breen, a veteran of Iraq and Afghanistan and executive director of the left-leaning Truman National Security Project. “They’re asking, ‘What was the last decade of my life for?’ Fairly or unfairly, they are looking to the president for an answer.”

Ashton B. Carter, the president’s likely choice for defense secretary, may not have the answers to those questions. Although Carter has spent much of his professional life around the military and the Pentagon, he has a reputation as a savvy technocrat with deep familiarity with the Defense Department’s weapons programs and budget process.

Focused on the day-to-day running of the military bureaucracy in Washington, he hasn’t been a major architect of the administration’s war strategies in Iraq and Afghanistan. Unlike many of his predecessors, he has never served in uniform or led troops in combat.

At the White House briefing on Tuesday, press secretary Josh Earnest spoke highly of Ashton Carter's past work with the Obama administration but stopped short of confirming rumors that the president will nominate him for secretary of Defense. (AP)

Now he will probably take over at a particularly perilous time for the military, which is dealing with steep budget cuts, an uncertain outcome in Afghanistan, and a mission in Iraq and Syria that Pentagon officials have said could stretch for years.

All are likely to deepen pre­existing tensions. The White House sought Tuesday to play down reports of recent acrimony. “There’s always some natural tension between the Pentagon and the White House,” said Josh Earnest, the White House press secretary.

The president can also point to some significant achievements on behalf of troops, including pay increases and a broad expansion of benefits available to veterans. In the battle against al-Qaeda and other terrorist groups, Obama has used drone strikes more aggressively than President George W. Bush in ­places such as Pakistan, Yemen and Somalia.

“This administration is stacking terrorists like cordwood,” said Phillip Carter, a senior fellow at the Center for a New American Security.

Such appeals, however, don’t necessarily resonate for soldiers and senior officers who have taken part in multiple tours of Iraq and Afghanistan and feel a deep emotional connection to the conflicts. “Some in the military are very uneasy at the prospect that both of these wars could be on the cusp of being lost causes,” said retired Lt. Gen. David Barno, who commanded U.S. forces in Afghanistan.

Unlike their Vietnam War counterparts, who were products of the draft era, many of today’s professional soldiers and officers have taken part in multiple tours of Iraq and Afghanistan. For much of the decade they have lived with their families in what one West Point professor has described as a “no man’s land,” somewhere between war and peace. They’ve come home to bases with stone memorials bearing the names of their fallen friends. They’ve kept in touch with war widows and their children.

“In a sense, they are saying, ‘We fought and we bled, and we are not willing to give this up,’ ” Barno said. “It is a much stronger sentiment in this force than anything I saw coming into the Army after Vietnam.”

Chuck Hagel, who was recently asked to resign as defense secretary, was supposed to be the kind of leader who could smooth that transition from war to peace. A decorated Vietnam veteran, Hagel understood the trauma of fighting a losing war as well as the vocabulary of leading and inspiring troops in combat.

As a former Republican senator from Nebraska, he also had close relationships on Capitol Hill. But Hagel had trouble penetrating Obama’s inner circle and was criticized by senior administration officials as being an inarticulate spokesman for the president’s policies.

In Carter, Obama has chosen someone who will be much more familiar with the inner workings of the Pentagon and someone who should able to make Washington’s largest bureaucracy run more efficiently. Although he hasn’t served in the military, Carter has developed close relationships with many of the military’s top brass over the course of decades.

He is also likely to be seen as a more effective advocate for the military inside the White House than Hagel, who some senior defense officials have criticized as unprepared and, at times, lacking as deep a knowledge of the issues facing the military as his predecessors.

Carter’s selection, though, won’t address the perception among some senior military officers that the president often lacks passion for their mission.

In Afghanistan, Obama has placed a high priority on cutting U.S. troop numbers during his final two years in office. The timelines, largely imposed by the White House, are intended to cap his generals’ ambitions and make good on his repeated promises to end the longest stretch of conflict in U.S. history.

White House officials say the limits reflect the president’s concern for the troops and their families. “One of the most difficult decisions the president has to make is the decision to send our troops into harm’s way,” said a White House official who spoke on the condition of anonymity to describe the president’s thinking on policy. “No one takes that responsibility more serious than President Obama. . . . The sacrifices that thousands of military service members and their families have made during the past 13 years serve as a constant reminder to the president that war takes a disproportionate toll on a courageous few.”

To many in the military, though, the long battles over exactly how many troops will remain in Afghanistan can smack of micromanagement. The repeated references to “exit paths” and “responsibly ending wars” can seem like evidence of a lack of presidential resolve.

“When did it become normal to announce years in advance the precise number of troops you are going to have in a conflict and think that gives you an advantage?” asked one Army general who has served multiple tours in Iraq and Afghanistan and spoke on the condition of anonymity to candidly discuss administration policy.

In Iraq and Syria, where U.S. attack helicopters are striking Islamic State insurgents and where soldiers are advising Iraqi forces, the president has mandated that American troops should not take part in combat. On a recent trip to Iraq, Army Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, fielded a question from a soldier asking why troops in the country didn’t qualify for combat patches and awards reserved for other war zones.

“The reason is that we’ve tied ourselves into a policy knot,” Dempsey recounted telling the soldier at a recent event in Washington.

Dempsey promised to fix the problem, but to some in the military, the White House’s insistence on referring to U.S. soldiers in Iraq as noncombat troops reflects a tone-deafness to military culture and a reluctance by the president to acknowledge that the United States is back at war in Iraq and Syria, fighting a determined enemy.

“By not calling it combat, that devalues the risks these troops are now going to be taking,” said Barno, the retired Army general who now serves as a senior fellow at the Center for a New American Security. “For most military folks, what you call it makes a big difference — especially if you are putting your life on the line. You risk breaking faith with your people if you ignore this.”