McKiernan is an excellent general in the old mold. McChrystal, who rose through the ranks as a special-forces officer, is an excellent general in the new mold. He has also worked closely with Gates and Petraeus. (In his press conference, Gates referred to McChrystal’s “unique skill set in counterinsurgency.”) For the past year, McChrystal has been director of the Pentagon’s Joint Staff. More pertinently, for five years before that, he was commander of the Joint Special Operations Command, a highly secretive operation that hunted down and killed key jihadist fighters, including, most sensationally, Abu Musab al-Zarqawi, the leader of al-Qaida in Iraq.

Last fall, Bob Woodward reported in the Washington Post that JSOC played a crucial, unsung role in the tactical success of the Iraqi “surge.” Using techniques of what McChrystal called “collaborative warfare,” JSOC combined intelligence intercepts with quick, precision strikes to “eliminate” large numbers of key insurgent leaders.