NEW : Sen. Lindsey Graham : withdrawl should only begin when conditions warrant it . Afghan and U.S. officials say it should stay until success is assured . Overall , Graham said , he found morale on the ground `` pretty good '' as Petraeus assumed command of the mission . Obama has said it would start in July 2011 . Withdrawal also depends on conditions on ground , Graham said .
NEW : Sen. Lindsey Graham : withdrawl should only begin when conditions warrant it . Afghan and U.S. officials say it should stay until success is assured . Obama has said it would start in July 2011 . Withdrawal also depends on conditions on ground , Graham said .