secretary penetta paid tribute to the men and women who served. >> your dedication, your commitment to this mission has been the driving force behind the remarkable progress that we see here in baghdad and across this country. >> reporter: about 4,000 american forces remn inside iraq. they're packing up and ready to handover the remaining two military bases. the nearly nine-year long war cost more than $800 billion. it claimed about 4500 american lives and left more than 30,000 troops wounded. the secretary says that sacrifice was not in vain. veteran groups point out even though the war is ending, for some troops the battles continue. >> don't turn the page on iraq just because they pulled out. and remember that a great thing you can do is hire a vet. >> reporter: unemployment among veterans is r than the national average. last month president obama took steps to change that. he signed a bill into law that gives businesses a tax credit for hiring veterans. >>> the final u.s. troops are supposed to be out of iraq by december 31st. but it appears that military officials will have to pul