The US is gradually developing and deploying space based anti-satellite weapons. StrategyPage reports:
March 5, 2014: The U.S. Air Force recently revealed that it is launching four GSSAP (Geosynchronous Space Situational Awareness Program) satellites that will spy on the most valuable and potentially dangerous (to the United States) foreign satellites. Not the low flying ones, which can be monitored from the ground, but the more expensive ones that operate in 36,000 kilometer high stationary (geosynchronous) orbits. Up there you have surveillance and communications satellites that basically stay over the same area on earth.
The four GSSAP birds are mobile and will move about in the geosynchronous orbits checking out the competition and, in particular, looking for satellites equipped to attack other satellites in that space. They may spur an arms race up there if other countries, particularly China, suspects that the GSSAP birds have a secondary attack function to knock out key (especially in wartime) Chinese commercial and military satellites in the geosynchronous region. The stated reason for GSSAP is to give the U.S. (and its allies) a better idea of who has what up there and to have that information first. Two of the GSSAP birds go up this year and the second two in 2016. Information on GSSAP satellites was made public to try and avoid paranoid and unpredictable reactions from nations with satellites up there once they noted the GSSAP birds moving about...." WHOLE ARTICLE