MILITARY

Hagel departure reflects White House unease, raises prospect of 1st woman to lead Pentagon

  • Defense Secretary Chuck Hagel, left, listens as President Barack Obama, right, talks about Hagel's resignation during an event in the State Dining Room of the White House in Washington, Monday, Nov. 24, 2014. Hagel is stepping down under pressure from Obama's Cabinet, senior administration officials said Monday, following a tenure in which he has struggled to break through the White House's insular foreign policy team. (AP Photo/Susan Walsh)

    Defense Secretary Chuck Hagel, left, listens as President Barack Obama, right, talks about Hagel's resignation during an event in the State Dining Room of the White House in Washington, Monday, Nov. 24, 2014. Hagel is stepping down under pressure from Obama's Cabinet, senior administration officials said Monday, following a tenure in which he has struggled to break through the White House's insular foreign policy team. (AP Photo/Susan Walsh)  (The Associated Press)

  • President Barack Obama, left, applaudes Defense Secretary Chuck Hagel, right, in the State Dining Room of the White House in Washington, Monday, Nov. 24, 2014. Hagel is stepping down under pressure from Obama's Cabinet, senior administration officials said Monday, following a tenure in which he has struggled to break through the White House's insular foreign policy team. (AP Photo/Pablo Martinez Monsivais)

    President Barack Obama, left, applaudes Defense Secretary Chuck Hagel, right, in the State Dining Room of the White House in Washington, Monday, Nov. 24, 2014. Hagel is stepping down under pressure from Obama's Cabinet, senior administration officials said Monday, following a tenure in which he has struggled to break through the White House's insular foreign policy team. (AP Photo/Pablo Martinez Monsivais)  (The Associated Press)

  • FILE - This Dec. 7, 2011 file photo shows former U.S. Defense Undersecretary Michele Flournoy, preparing for a bilateral meeting in Beijing, China. Flournoy, formerly the Pentagon's policy chief and among President Obama's more hawkish advisers, could be in line to become the first woman to lead the U.S. military after Defense Secretary Chuck Hagel's resignation.  (AP Photo/Andy Wong)

    FILE - This Dec. 7, 2011 file photo shows former U.S. Defense Undersecretary Michele Flournoy, preparing for a bilateral meeting in Beijing, China. Flournoy, formerly the Pentagon's policy chief and among President Obama's more hawkish advisers, could be in line to become the first woman to lead the U.S. military after Defense Secretary Chuck Hagel's resignation. (AP Photo/Andy Wong)  (The Associated Press)

Defense Secretary Chuck Hagel is quitting at a messy moment for U.S. foreign policy, with one war ending and another just beginning.

His forced departure reflects White House concerns about his effectiveness and raises the prospect of policy shifts as President Barack Obama looks to sign up his fourth Pentagon chief in six years.

Hagel said Monday he will stay until a successor is confirmed by the Senate.

Among the leading candidates is Michele Flournoy, a former Pentagon policy chief who would be the first woman to serve as defense secretary.

In a White House announcement Monday, Obama said he and Hagel agreed it was an "appropriate time for him to complete his service." Hagel is the first enlisted combat veteran to head the Pentagon.