Foreign Policy

The US military dominates US foreign policy, and the brass don't like Hagel because he puts America first and that means he resists foreign wars more than the standard neocon.

"Since the 9/11 attacks, US foreign policy has become highly militarized. The Pentagon today dominates US relations with the rest of the world, not the State Department or CIA.
The Pentagon’s 2013 total budget will be $800 billion when all programs, including "black" projects, are included.
This mammoth sum represents almost 50% of the world’s total military spending. Add close US allies in Europe, the Mideast, and Asia, and the figure is 80%.
Contrary to what most Americans believe, the US Defense Department is not really about defense of America’s shores, but about offensive operations abroad. The US has some 1,000 bases and powerful air, naval and land forces scattered across the globe enforcing the Pax Americana."

We're paying for our government's aggression with blood and treasure.

"But something remarkable has just occurred in Washington, a place that rarely produces much good news.
President Barack Obama, now in his last term and freed of many political constraints, has challenged powerful vested special interests by naming former US Republican Senator and decorated war veteran Chuck Hagel as Secretary of Defense. Hagel, wounded twice in Vietnam, is the first former enlisted man to head the Pentagon.
On taking office, Hagel called on the US to resume being a "force for good" in the world and avoid "dictating" to other nations. These were breathtaking words after all the Republican claims of "American exceptionalism" – code for world domination."

Obama is not going to make the US a force for good.