Just in case it wasn't obvious what a 4000 mile per hour DARPA glider was designed to be used for, here are the details for a weapon that can take out North Korean nuclear missles while they are being fueled on the launch pad -- with an hour's flight time.
http://www.google.com/hostednews/ap/article/ALeqM5j2OEe40ELUOvey0lnDA_n4_DzcDAD9F8TNE80WASHINGTON — In coming years, President Obama will decide whether to deploy a new class of weapons capable of reaching any corner of the earth from the United States in under an hour and with such accuracy and force that they would greatly diminish America’s reliance on its nuclear arsenal.
Called Prompt Global Strike, the new weapon is designed to carry out tasks like picking off Osama bin Laden in a cave, if the right one could be found; taking out a North Korean missile while it is being rolled to the launch pad; or destroying an Iranian nuclear site — all without crossing the nuclear threshold. In theory, the weapon will hurl a conventional warhead of enormous weight at high speed and with pinpoint accuracy, generating the localized destructive power of a nuclear warhead.
But since the vehicle would remain within the atmosphere rather than going into space, it would be far more maneuverable than a ballistic missile, capable of avoiding the airspace of neutral countries, for example, or steering clear of hostile territory. Its designers note that it could fly straight up the middle of the Persian Gulf before making a sharp turn toward a target.
The Pentagon hopes to deploy an early version of the system by 2014 or 2015. But even under optimistic timetables, a complete array of missiles, warheads, sensors and control systems is not expected to enter the arsenal until 2017 to 2020, long after Mr. Obama will have left office, even if he is elected to a second term.
U.S. Faces Choice on New Weapons for Fast Strikes