Ashton Carter, whom President Obama selected to be the next secretary of defense on Friday, is in many ways the opposite of his predecessor, Chuck Hagel.

Hagel was a decorated Vietnam veteran, former GOP senator from Nebraska and Pentagon outsider. Carter never wore the uniform, never held elected office and has been a Pentagon insider, serving in multiple high-level leadership roles during the Clinton and Obama administrations. An academic with multiple degrees, including a doctorate in theoretical physics from Oxford, Carter's considered an intellectual technocrat familiar with the complex defense budgeting and procurement process.

That's essential for any secretary of defense, but especially during an era when fiscal restraint — including cuts in military spending under the sequester — has had such a dramatic impact on the military.

There are other important intra-military matters that need attention at the highest level, including an appallingly high number of sexual assaults. A report released last week showed that rapes and sexual assaults increased 8 percent in fiscal year 2014. More than 5,400 cases were reported, but that's just a fraction of the 26,000 women, and men, estimated to be victimized in 2012. To be sure, Hagel and other military leaders were demonstrably concerned, but much more leadership is needed to eliminate this stain on the armed forces.

Regarding military matters, the Obama administration faces several key decisions. Among them are deployment of resources to bolster the diplomatic "pivot" to Asia that the administration considers essential to manage China's rise and contain North Korea's nuclear menace (on this issue Carter is considered a hawk). He also must work to strengthen NATO's military posture in response to Russian aggression. Multiple decisions are needed on multiple weapons systems, and America's aged — and, many say, oversized — nuclear arsenal needs to be addressed, too.

But on a more immediate basis, the administration must remain flexible on Afghanistan, lest the end of combat operations next year create a similar situation as happened in Iraq. Failure to agree on a status of forces agreement (as well as an incompetent Iraqi military that remained after the U.S. withdrawal) contributed to conditions that allowed ISIL, the Islamic State of Iraq and the Levant, to take over a significant portion of the country after it had conquered broad swaths of Syria.

Ashton Carter

Obama has given the military the mission to "degrade and ultimately destroy" ISIL. Carter should be pressed during congressional confirmation hearings for his view on the role, if any, that U.S. combat troops should have in the fight. He should also be asked whether Iraqi troops and Kurdish Peshmerga forces are sufficient to turn back ISIL in Iraq, and if Kurdish and "moderate" Syrian forces, which are being trained by the United States, are any match for ISIL in Syria. And to what degree does targeting ISIL protect Syrian President Bashar Assad's regime, which has killed many more than ISIL has?

Ultimately, policy decisions need to be made by elected officials in the executive and legislative branches, not by those in the Pentagon. But Obama and congressional leaders need the unvarnished truth from the military, even if it doesn't square with optimistic outlooks.

Obama is right to reach for a new approach and to pick a person who reportedly will not quickly acquiesce to White House political pressure. Accordingly, Obama and his White House national security team need to act differently than they did with Hagel.

Over six years and now three secretaries of defense, there have been widespread, repeated reports of the Pentagon being micromanaged or thwarted by a clique of administration officials. The pervasive nature of this characterization suggests that this counterproductive pattern needs to end.

As secretary of defense, Carter should respectfully make it clear to the commander in chief and to Congress that while he respects White House and congressional authority, he would serve the nation best by being trusted to do his job.