I guess I will bypass the obvious question of who you would rather have controlling space.

Our military has become quite dependent on space resources, especially our precision weapons and communications systems.

It goes without saying that we need to develop systems to help defend these military resources, as well as civilian space resources*. A large military space presence would also go a long way to making missile defense and other systems more feasible.

The U.S.S.R. had many plans for militarizing space, including armed space stations and systems for destroying other space vehicles. Fortunately, few of these panned out.

*Any rocket with the capacity to fly a ballistic mission 200 miles straight up could blow the ISS out of the sky. A large shrapnel warhead detonating in the path of the ISS would tear it to bits. The trick would be simply timing and trajectory...the shrapnel cloud would have to intersect the oncoming space station before it all fell back to Earth in a minute or so. How accurate the missile would have to be would largely depend upon the size of the warhead and the diameter of the resulting shrapnel cloud.