What this means is that any vehicle which has a high degree of operational flexibility can and will be used for all sorts of things. It means that there's more to SSTO than satellite launch. These roles are possible because fighter jets are robust and versatile. The Black Horse will make a huge leap in versatility by adding trans-atmospheric and orbital flight capability, without sacrificing ease of mission planning. Useful to the USAF, and makes use of USAF assets.
Flexibility is the key to air power, and air power is the key to victory.
A Black Horse would have tremendous military application because it would allow US Space Command to put as many satellites in orbit as they want and, more importantly, whenever they want. Another part of Space Command's mission is the negation of enemy space assets, which can only be done easily with a flexible launch vehicle like the Black Horse. Furthermore, it would put American forces anywhere on Earth within an hour of takeoff. The military is the only organization which really has experience with aerial refueling, and they are the only people who have the capability to do it. Thus, since they can maintain control of it, it encourages them to build it.