Washington: With Gen. Martin Dempsey the Pentagon may have gotten just who it wanted for its new Chairman of the Joint Chiefs, but he may not be the man who is really needed right now.

The four-star general is set to go before the Senate Armed Services Committee tomorrow morning to make his case to replace current Chair Adm. Mike Mullen, after beating out current vice chief and presumed shoe-in for the chairman’s seat Gen. James Cartwright in an ugly smear campaign that sealed both officer’s fates.

But Cartwright’s fall from grace, and Dempsey’s subsequent rise to the top of the White House’s list, has seemed to set the tone for DoD under the Obama administration: Don’t rock the boat.

That is a job description that fits Dempsey, outgoing Army chief of staff, to a T, says one Capitol Hill aide.

“I absolutely think that is what he is going to be, and that is one of the reasons Cartwright was not picked,” the aide said. Cartwright had a reputation of being a “stir-the-pot kinda guy” going back to his days heading up Strategic Command, the aide said.

Questioning the Air Force’s need for a new strategic bomber, suggesting the Navy may not need a new aircraft carrier and predicting that America will have to go on the offensive in the realm of cyberwarfare are just a handful of ideas that provide a glimpse into what Cartwright would have brought to the table.

“My guess is [Dempsey] is not that,” the aide added, echoing comments by three other close observers of the military on the Hill and in the defense industry.

Dempsey is not well known to decision makers on the Hill, aside from his time as chief of Army Training and Doctrine Command and his most recent stint as Army Chief of Staff.

“He is not like one of these guys who was here all the time,” the Hill aide said.

But one thing Dempsey had over Cartwright was time in the field. He led the Army’s 1st Armored Division during the early days of the Iraq War. The four-star general also headed up the Multinational Security Transition Command in Iraq from 2007 to 2008.

Cartwright and Dempsey both took very analytical, pragmatic approaches to some of DoD’s most pressing matters, even though Cartwright may have gotten more of the limelight within the department, according to a second Hill aide.

Where they differed, the second staffer added, was in how they won friends and influenced people within their respective organizations.

Once confirmed, Dempsey will be front and center on some of the most pressing national security issues facing the Pentagon — from American withdrawal plans from Iraq and Afghanistan to his ideas on how to keep America’s fighting forces ready in a tough budget environment.

While Dempsey’s responses tomorrow probably won’t provide much insight into how he plans to address those issues (nominees rarely tip their hand during confirmation hearings), the four-star general certainly has the intellectual chops to handle those tough calls, the second staffer said.

The problem is that America’s military forces are at a crossroads and the only thing certain within DoD is that things are going to have to change. And many observers we spoke with –not all — believe Dempsey may not push hard to change policies and practices.

The second Hill aide said much of what happens, in the end, may well come down to what new Defense Secretary Leon Panetta wants to do. And what that may be, no one really knows yet.

Under Cartwright, changes could have been driven into the department from the top down by a dynamic military leader willing to push hard for policies he believed in. Under Dempsey, the department is more likely to react and not drive those changes the Pentagon must make, most of our sources said.