Secretary of Defense Chuck Hagel is out. Whether it's because he just wasn't cut out for the job or is a convenient scapegoat for an administration bedeviled by a slew of foreign policy crises, is up for debate. But what's clear is that by the end of his tenure he had been eclipsed by the military, whose clout has only risen in recent months. Here's the report from Helene Cooper at The New York Times:

[I]n the past months he has largely ceded the stage to the chairman of the Joint Chiefs of Staff, Gen. Martin E. Dempsey, who officials said initially won the confidence of Mr. Obama with his recommendation of military action against the Islamic State. [The New York Times]

That points to the broader problem with Hagel. He no longer fit in an administration that has fallen back on the default setting for American foreign policy: endless war.

Hagel was selected to head the Pentagon for the same reason that President Obama was originally elected: He bluntly recognized the failure of the Iraq War (not beforehand, but by 2004 or so). He was supposed to be the guy who managed the end of major wars and placed America's military on a less aggressive footing.

Instead, the administration has found itself unable to extract the military from the mires George W. Bush left in the Islamic world.

Our exciting new Iraq War III: Now Including Syria (which is still illegal, by the way) is already a fiasco. The CIA is deeply involved in arming and training only-God-knows-who, even though a historical review by the agency concluded that arming rebels almost never works. Meanwhile, the U.S. military is stuck arming and training an Iraqi army that evaporated in the face of ISIS despite being given hundreds of millions of dollars by the American taxpayer, and that is probably way too corrupt to ever stand up on its own.

The U.S. is also sticking around Afghanistan, despite the fact that the Obama administration has been planning to end the U.S. presence there for years now. Troop deployments are scheduled to fall to about 10,000 or so by the end of this year, when U.S. forces were supposed to move to noncombat roles. Britain packed up and left last month. But over the past week or two, the administration has announced what amounts to a major military re-commitment to that conflict.

The new rules of engagement will allow the Pentagon to authorize combat, including air strikes, under many different circumstances. Nighttime raids, hated by Afghan civilians, are back in play. The reduction in troop levels is also in question, with Obama announcing that forces will be beefed up by 4,000 for the moment, due to the worsening insurgency.

With the U.S. shifting back to a war footing, Hagel's input was apparently no longer needed.

The question, as always, is how long America is willing to keep this up. The war in Afghanistan alone is already projected to cost $4 trillion. The Taliban, sensing U.S. exhaustion, have been conducting aggressive operations for months now and secured some major victories. Does anyone think the latest policies are going to make a difference?

The U.S. is caught in a trap. It can't withdraw from these countries without them falling to pieces. It can't achieve anything of lasting significance, either. A frank admission of the limits of American power is just something we can't handle as a nation — and so Hagel had to go.