The ABL was designed for use against tactical ballistic missiles (TBMs).
These have a shorter range and fly more slowly than ICBMs.
 The MDA has recently suggested the ABL might be used against ICBMs during their boost phase.
This could require much longer flights to get in position, and might not be possible without flying over hostile territory.
 Liquid-fueled ICBMs, which have thinner skins, and remain in boost phase longer than TBMs, might be easier to destroy.

If the ABL had achieved its design goals, it could have destroyed liquid-fueled ICBMs up to 600 km away.
 Tougher solid-fueled ICBM destruction range would likely have been limited to 300 km, too short to be useful in many scenarios, according to a 2003 report by the American Physical Society on National Missile Defense.
The ABL was designed for use against tactical ballistic missiles (TBMs). These have a shorter range and fly more slowly than ICBMs.  The MDA has recently suggested the ABL might be used against ICBMs during their boost phase. This could require much longer flights to get in position, and might not be possible without flying over hostile territory.  Liquid-fueled ICBMs, which have thinner skins, and remain in boost phase longer than TBMs, might be easier to destroy.
If the ABL had achieved its design goals, it could have destroyed liquid-fueled ICBMs up to 600 km away.  Tougher solid-fueled ICBM destruction range would likely have been limited to 300 km, too short to be useful in many scenarios, according to a 2003 report by the American Physical Society on National Missile Defense.
Boeing YAL-1