From the AP:
There are two points to be made here. First, as far as putting offensive weapons in space, no state has yet done anything of the kind, and no state is likely to do so any time soon. Only the United States has the resources and technological expertise to really work toward weaponizing space–and even then it isn’t clear that, after a careful cost-benefit analysis, such systems will ever make it off the drawing board. But land-based ASAT weapons are another story. The United States was successfully testing ASAT systems in the mid-1980s, and the Russians had started developing their own ASAT capability as early as the 1960s. The right to maintain a ground-based ASAT capability would not be hindered by a treaty banning space weapons, giving China the chance to further refine its capabilities in that area, and making America’s network of satellites that much more vulnerable in the event of conflict. Even if such systems were included in the proposed treaty, there would be no conceivable way to verify compliance by China and Russia. As James Oberg’s explained in the pages of THE WEEKLY STANDARD, only the United States would be forced to comply with such an arms control regime. The Chinese and Russians are cynically pushing this treaty because they know that it would seriously constrain the United States from building on its already formidable advantage in space. But it would do nothing to prevent China and Russia from pursuing weapons systems that would nullify that advantage. Still, the Western media will report this story as another instance of the Bush administration’s unilateralism. Says Oberg, “The manipulation of Western media and political forces in that direction [of an international treaty], at the point of a space gun, is a good payoff for blowing up one surplus satellite.”

