Potential successors to Army Gen. Stanley McChrystal as commander of forces in Afghanistan:

—Marine Gen. James Mattis, commander of U.S. Joint Forces Command in Norfolk, Va. He has command combat experience in Afghanistan and Iraq. He was passed over as commandant of the Marine Corps this month.

—Marine Lt. Gen. John Allen, the deputy commander of U.S. Central Command, under Gen. David Petraeus, since 2008. From 2006-2008, Allen commanded the Second Marine Expeditionary Brigade in Iraq.

—Army Lt. Gen. David Rodriguez, McChrystal's No. 2 in Afghanistan. The two men were sent to Afghanistan as a package deal, with plans for Rodriguez to run the war day to day while McChrystal focused on the bigger picture. He previously served as a military adviser to Defense Secretary Robert Gates.

—Army Gen. Martin Dempsey, commander of the Army Training and Doctrine Command since December 2008. Dempsey commanded the effort to train Iraqi security forces for two years, ending in the summer of 2007. He stepped in as acting commander at Central Command after Adm. William Fallon was forced out. Fallon was done in by an article in Esquire magazine, which described him as the bulwark between the Bush administration and war with Iran.

—Navy Adm. James Stavridis, the top NATO commander in Europe. He assumed duties as Commander of the United States European Command in June 2009 and as the Supreme Allied Commander, Europe in July 2009. From 2006-2009, he commanded U.S. Southern Command in Miami, focused on Latin America and the Caribbean.