WASHINGTON – President Barack Obama announced Monday morning that Defense Secretary Chuck Hagel resigned his position. Obama didn’t announce a replacement for the top Pentagon job, nor did he give a reason or policy difference for Hagel's departure. Instead, the president praised Hagel and despite reports that he was being pushed out, made clear the departure will be smooth.

“We come from different parties, but in accepting this position you sent a powerful message, especially to folks in this city, that when it comes to our national security and caring for our troops and their families, we are all Americans first,” Obama said.

In a brief appearance that included Hagel, Obama praised the outgoing secretary’s time not only as the head of the Pentagon, but also his work as a senator and head of the USO in helping troops and veterans throughout the years.

“Chuck Hagel has been no ordinary secretary of defense,” Obama said, pointing out he was the first enlisted veteran to hold the job. “He stood where they stood, he’s been in the dirt and he’s been in the mud.” Obama added, “I consider myself extraordinarily lucky to have Chuck by my side the last two years.”

Hagel thanked the president and Vice President Joe Biden, who also attended the event but did not speak, for being able to serve in the role. “I will continue to support you, Mr. President, and the men and women who continue to defend our country every day,” Hagel said. “I will stay on this job and work just as hard as I have over the past couple of years every day.”

The process to find and confirm a replacement for Hagel could be lengthy and contentious. The new Republican-controlled Senate will include a number of hawks, particularly Sen. John McCain, R-Ariz., who will want to hear aggressive plans for the fight against ISIS.

Hagel, the former Nebraska senator, assumed the role of secretary of defense in February 2013. At the time, the wars in Iraq and Afghanistan were winding down. The Pentagon was dealing with budget cuts because of sequestration – the deal struck by Republicans and Democrats that split spending cuts between Defense and domestic programs.

Less than two years later, the nation is re-engaged in fights in the Middle East and instead of grappling with budget cuts are trying to find $5.6 billion more to fund the fight against ISIS.

Obama acknowledged that shift in mission for the Pentagon, saying Hagel has worked to refocus the Pentagon to address the future. “Chuck has ensured that our military is ready for new missions,” Obama said.

News leaked out Monday morning that Hagel will be departing after less than two years as the head of the Defense Department. There immediately were differing takes on why Hagel, a former Republican senator, was exiting after such a brief stint in the job. Some suggested Obama was pushing Hagel out of the role, while others said it was mutual and both parties had reached the end of their ropes.

The New York Times reported that Hagel was failing to mesh with the rest of the Obama administration and wasn’t able to break into the president's inner circle. According to the Times, Hagel was failing to defend White House positions in public. CBS News reported that Hagel was “fed up with micromanagement from the White House.” 

The timing was interesting as well.

On Monday, the White House announced that the extendsion of a deadline to complete a deal with Iran to stem the nation’s nuclear program development.

And the announcement came in the midst of White House trying to determine how to move forward with the fight against the Islamic State in Syria and Iraq. The White House has expressed a desire to see a new authorization to fight ISIS, but so far has not made a direct appeal to Congress to pass a bill.

The next secretary of defense will inherit the existing problems with the fight against ISIS. Hawkish members of the Senate will be pressing heavily for an aggressive plan to combat the terrorist group. Those like McCain, who has argued in favor of ground troops, will be responsible for the nomination process to approve the next nominee.