and as u.s. troops begin to leave, violence is increasing in the heart of kabul. just last week, insurgents launched a 20-hour attack on the u.s. military headquarters and the u.s. embassy. you can still feel the tension in the air outside of rabbani s house just behind me. his death was so important, president karzai cut short a trip to new york to return immediately. he has declared three days of national mourning for rabbani. abc news, kabul. and before he left for home, afghan leader karzai held talks with president obama at the united nations. mr. obama vowed the tragic events would not prevent peace talks from going forward or prevent the withdrawal eventually of u.s. troops. but president karzai was far more somber, saying that it won t be easy to replace him at the peace table. legendary man. yes, indeed. president obama remains focused on problems in the middle east during his u.n. meetings today. the white house announced mr.