US President Barack Obama is set to announce Tuesday his plan to draw down the current force of 32,000 US troops when they end their Afghanistan combat mission by the end of 2014, and leave 9,800 to train Afghan forces and support counter-terrorism operations. Those numbers are contingent on Kabul signing a bilateral security agreement. This, the incumbent president Hamid Karzai has refused to do. The administration appears confident that both of the candidates to replace him in the June 14 run-off will come around to signing.