their nato and afghan partners. we are a nation at war." the human toll of the surge was tremendous. of the almost 2,000 u.s. casualties in afghanistan, 57% happened during the surge. now those who remain face the die-hard insurgents and the growing threat of insider attacks. the deadline to bring the final american troops home is still 2014. muhammad leila, abc news, kabul. zbhood news there, important to point out. 68,000 americans still in harm's way and still fighting. >> until the end of 2014. >> the danger now from insider attacks. three people killed last week. another one killed the week from afghan forces and being attacked working alongside americans. you're expecting the enemy over there, not next to you. >> dubious. straight on-attack. >> for sure. >> it's got to be a frightening situation to be in, you don't know who to trust.