washington taliban increase amount territory influence control afghanistan past six months u.s. watchdog agency report tuesday militant group step attack recent weeks august 13 percent 407 district afghanistan taliban control influence compare 11 percent february accord report special inspector general afghanistan reconstruction sigar mean additional 700,000 people live district taliban least influence update figure sign deteriorate security situation war-torn country even unite state commit several thousand troop gain make taliban spate recent attack underscore worry afghan security force ability deal relentless insurgency struggle contain since foreign troop leave end 2014. total 43 percent afghanistan district either taliban control contest three percent high six months ago sigar say u.s. force afghanistan also withhold certain data afghan national defense security force report say include casualties personnel strength attrition operational readiness equipment significant development quarter u.s. forces-afghanistan usfor-a classify otherwise restrict information sigar publicly report report say afghanistan worsen security situation highlight tuesday suicide bomber capital kill many eight people islamic state claim responsibility attack increase campaign u.s. air strike recent months part new strategy aim reverse taliban gain force insurgents seek peace talk afghan government sigar report cite unite nations assistance mission afghanistan also say 52 percent increase civilian casualties coalition afghan air strike first nine months 2017 compare period 2016. also sharp increase insider attack militants target u.s. afghan force june three americans kill one wound afghan soldier open fire taliban increase influence territory afghanistan u.s. watchdog