By YOCHI J. DREAZEN ( Wall Street Journal)

WASHINGTON — The Pentagon is setting up a unit of about 400 officers and senior enlisted personnel devoted to Afghanistan, continuing a broad revamp of how it handles the war there.

The Pakistan Afghanistan Coordination Cell is the creation of Lt. Gen. Stanley McChrystal, the Obama administration's nominee to run the Afghan war. Gen. McChrystal says he wants military personnel to accumulate expertise about the war by doing repeated deployments to Afghanistan and continuing to work on the conflict when back in the U.S.

The unit will be headed by Brig. Gen. Scott Miller, a veteran of the military's secretive Special Operations community, who worked for Gen. McChrystal at the Pentagon. The unit is meant to develop personnel with extensive counterinsurgency experience and knowledge of Afghanistan's culture and power structures.

"The biggest complaint we hear from Afghans is that they get to know a new unit, spend a few good months working with them, and then the troops redeploy and are never seen again," a senior military official said. "This is a way of capturing some of that expertise."The move represents a significant shift from the military's system of rotating troops among assignments in Iraq, Afghanistan, and home bases in the U.S., Japan and Germany.Personnel in the new unit will rotate between the U.S. and repeated Afghan deployments to the American-led headquarters in Kabul, the U.S. regional command in eastern Afghanistan, and the North Atlantic Treaty Organization-led command in the southern part of the country, according to senior military officials.The Pentagon is working to restructure the U.S.-led war effort and reverse the Taliban's recent gains. In May, Defense Secretary Robert Gates ousted the current commander, Gen. David McKiernan, and announced plans to replace him with Gen. McChrystal.Gen. McChrystal was confirmed by the Senate Wednesday and should be on the ground in Kabul before the end of the month. A second senior commander, Lt. Gen. David Rodriguez, is being sent to Afghanistan to handle the war day-to-day.The Obama administration has signed off on sending 21,000 American reinforcements to Afghanistan by the end of the year, pushing U.S. troop levels to their highest point since the start of the war in October 2001.The Pakistan Afghanistan Coordination Cell grew out of a classified review of U.S. operations in Afghanistan that Gen. McChrystal conducted for Adm. Mike Mullen, chairman of the Joint Chiefs of Staff.