Defense Secretary Chuck Hagel resigned under pressure on Monday after President Obama determined that he had to shake up his national security team in the face of escalating conflicts overseas and hawkish Republicans reasserting themselves on Capitol Hill.
It was a striking reversal for a president who chose Mr. Hagel two years ago in part to limit the power of Pentagon officials who had repeatedly pushed for more troops in Afghanistan and a slower drawdown of American forces from Iraq. But in the end, Mr. Hagel’s passivity and lack of support in Mr. Obama’s inner circle proved too much for an administration that found itself back on a war footing.
Aides said Mr. Obama made the decision to remove his defense secretary on Friday after weeks of rising tension over a variety of issues, including what administration officials said were Mr. Hagel’s delays in transferring detainees from the military prison in Guantánamo Bay and a dispute with Susan E. Rice, the national security adviser, over Syria policy.
