President Obama formally announced Chuck Hagel’s resignation from his post as secretary of defense on Monday, less than two years after a long and painful confirmation process to install him in the job. Obama said that Hagel concluded it was an “appropriate time for him to complete his service.” He praised Hagel as “no ordinary secretary of defense,” citing how his military service during the Vietnam War helped him establish a “special bond” with troops. Obama also said Hagel will stay on as secretary of defense until a successor is selected and sworn into office. In the summer, Hagel, a Republican, appeared to contradict Obama’s assessment that ISIS was a “JV team.” White House officials later described Hagel’s remarks as unhelpful. White House insiders say Hagel never penetrated the circle of Obama loyalists, despite carrying out the president’s goals of trimming the Pentagon budget and bringing back troops from Afghanistan. The short list of successors includes Michèle Flournoy, a former undersecretary of defense; Sen. Jack Reed (D-RI); and Ashton B. Carter, former deputy secretary of defense.