What is the news item mainly about? [originaltext] American forces in Afghani

American forces in Afghanistan have launched their first offensive since President Obama announced more troops for the war. On Friday, military officials said more than one thousand NATO troops, mostly Americans, launched the operation with Afghan forces. Troops moved in to clear Taliban insurgents and explosives from the Now Zad valley in the southern province of Helmand.
    On Tuesday President Obama told Americans that thirty thousand more troops will go to Afghanistan as fast as possible. And he announced that after eighteen months, in July of two thousand eleven, " our troops will begin to come home. "