The improvementofmotor's combustionvelocity to shorten the action time and reduce the height of boostphaseis an effectivemethod for antiboostphase interception.
Thus, boost-phase interception requires very prompt detection of a missile launch -- which adverse cloud and weather conditions can make difficult or impossible.
The initial, boostphase is the best time for defenders to achieve interception, because the lofting missile is relatively easy to track and one hit may kill multiple warheads.