washington president barack obama approve give u.s. military great ability accompany enable afghan force battle resilient taliban insurgency move assist proactively battlefield u.s. official tell reuters senior u.s. defense official speak condition anonymity say decision would also allow great use u.s. air power particularly close air support however official caution blanket order target taliban obama decision redefine america support role afghanistan grind conflict year international force wrap combat mission shift burden afghan troop also come ahead obama eagerly anticipate decision whether forge ahead schedule reduction number u.s. troop 9,800 currently 5,500 start 2017. group retire general senior diplomats urge obama last week forgo plan warn could undermine fight afghan taliban whose leader kill u.s. drone strike pakistan last month new policy u.s. commander afghanistan general john nicholson able decide appropriate american troop accompany conventional afghan force field something far afghan special force official say expand power mean employ select instance engagement enable strategic effect battlefield official say mean u.s. force expect accompany afghan soldier day-to-day missions add flexibility ... fully support afghan government help afghans important moment country official say decision departure current u.s. rule engagement afghanistan impose limit u.s. force ability strike insurgents example u.s. military previously allow take action taliban extremis moments assistance need prevent significant afghan military setback definition however leave u.s. military posture assist defensive instance new policy would allow u.s. force accompany afghans key moments offensive campaign taliban u.s. force proactively support afghan conventional force official say taliban control contest territory afghanistan time since oust u.s.-backed intervention late 2001 u.s. officials acknowledge uneven performance afghan security force large portion afghanistan include provincial capital northern kunduz multiple district southern helmand province fall time briefly taliban past year-and-a-half many district provinces also vary degrees taliban control new authorities obama give u.s. military could give great leeway address shortcomings afghan security force still experts warn hard predict afghanistan able stand taliban mention country enormous economic difficulties fractious political system u.s government top watchdog afghanistan tell reuters unite state waste billions dollars reconstruction aid afghanistan past decade renew taliban insurgency threaten gain make exclusive obama approve broad role u.s. force afghanistan