trucks, but they also have more tars, and overwhelming forces coming in in the air. when you're talking about combines a-10s and f-15s with ground forces in a desert environment, you have a significant advantage over isis, which doesn't have those aircraft. >> reporter: the pentagon considering further expansion, including more special operations forces for raids in syria and iraq against isis leadership, more apache helicopter gunships for low-eight attitude attacks and possibly u.s. forward air controllers on the ground to help pick out targets. u.s. troops in iraq may in and out be based with smaller iraqi units closer to the front lines. a u.s. official tells cnn the russians are also expanding their now now flying from a third air base just as the