Defense Secretary Robert M. Gates asked for the resignation today of the top US commander in Afghanistan, Gen. David McKiernan, and recommended that the critical job go to veteran Special Operations commander Lt. Gen. Stanley McChrystal.

    Gates made the announcement in a hastily called Pentagon news conference along with Chairman of the Joint Chiefs of Staff Adm. Mike Mullen at 2 p.m. today.

    Gates said he felt "a fresh approach, fresh look in the context of the new strategy was appropriate."

    The leadership shift comes as the Obama administration works to execute a new counterinsurgency strategy for Afghanistan and Pakistan to quell surging violence in those countries.

    McChrystal is currently the director of the joint staff. From 2006 to August 2008 he was the forward commander of the U.S. military's secretive Joint Special Operations Command, responsible for tracking down high-level leaders of the Sunni insurgent group al-Qaeda in Iraq, including its former leader, Abu Musab al-Zarqawi, who was responsible for a brutal campaign of bombings and beheadings until he was killed by U.S. Special Operations Forces in April 2006.

    McKiernan took command of the NATO-led mission in Afghanistan in the summer of 2008, and like other top U.S. commanders before him, he has pressed the Pentagon to provide additional forces to combat rising violence and an escalating Taliban insurgency. He oversaw initial troop increases under the Bush administration as well as the ongoing increase of 21,000 troops this year ordered by President Obama. McKiernan also worked to reduce Afghan civilian deaths from coalition military operations, although such incidents continued to occur, drawing criticism from Afghan officials.