NEW : U.S. troops did ` ` truly remarkable '' things in Iraq , Austin says . ` ` Welcome home , '' Joint Chiefs chairman tells him . Today 's ceremony was the formal end of the U.S. military mission in Iraq . As many as 4,500 Americans were killed in the nearly civil war .
NEW : U.S. troops did `` truly remarkable '' things in Iraq , Austin says . `` Welcome home , '' Joint Chiefs chairman tells troops . Tuesday 's ceremony was the formal finale of the U.S. military mission in Iraq . As many as 4,500 Americans were killed in the nearly 9-year war .