I agree completely that the X-37 makes no apparent sense. The only argument I can come up with is that returning is just a nice side effect of its real purpose: inclination changes. Chaning altitude and period and phase is all relatively easy with onboard thrusters (and X-37 has an orbital maneuvering engine almost as big as the Space Shuttle's). But the amount of thurst needed to change oribal inclination from, say equatorial to ISS, is vast. I calculated it recently as being equivalent to the delta-v provided by an earth to LEO launch.

What X-37 might be capable of is dipping into the atmosphere, banking, then thrusting back up to orbit. That's exactly what the Air Force's previous space plane was designed to do, the Dyna-soar. Once one has this capability, returning from orbit to a runway landing is a freebie since you already have the wings.

The recently concluded X-37 test flight did not show an inclination change. But look for it on a future flight. This would allow extreme flexability in imaging enemy action at completely unpredictable times.

Docking of course is just the first step. One also needs agreement on the atmosphere. American spacecraft (Apollo, Skylab) used 100% oxygen at 5 psi. Soviet spacecraft (Soyuz, Salut, Mir) used 20% oxygen 80% nitrogen at 14.7 psi. Neither side could change this easilly. Thus even though Apollo and Soyuz were able to physically dock in 1975, they had to use an airlock between the two spacecraft. Otherwise the cosmonauts would have gotten the bends from decompression and Apollo could have ruptured from overpressure.

Fortunately this is no longer much of an issue. As a result of the Apollo 1 fire and the deaths of Grissom, White and Chaffee, American spacecraft (starting with the Space Shuttle) adopted the Soviet approach.

Even in a battlefield devoid of both enemy and non-combatants, when to shoot or not can be extremely difficult. Consider the case (which occurred in Iraq) where one group of soldiers are fired upon by another group from the same side. Yes, that's a tragic blue-on-blue action. But the interesting question is what should the soldiers on the receiving end do? Assuming communications aren't working, do they:
a) Sit back and get slaughtered.
b) Fire back and take out the aggressors.
One consideration is the size of the forces involved. Another consideration is the importance of the missions each side is involved in.

Making a robot handle these cases would be interesting.