Question about ABL.

We all know about the ability of future airborne laser to shoot down theater balistic misiles, but could it also be used against lower flying targets like cruise missiles aircrafts? The ABL laser beam should have no problems in space or thin upper atmosphere but what about it's performance in lower atmosphere? Will it have decreased range or would it be not able to engage targets lower than 15000 meters? I know that THEL beam works quite good up to 20-25 miles in low altitudes, but what about ABL? Or is it designed only to engage balistic missiles?

[Edited on 25-5-2004 by longbow]