After watching 'Guardians of the Galaxy', one thing struck me as odd after getting over the sheer spectacle of the film; what the hell was the Xandarian military doing when Ronan invaded their homeworld, which was completely exposed save for the Nova Corps (a glorified police force in the movie's universe)?
With the Kree War concluded for almost everyone involved (obviously not for the extremists on both sides), there was little to no excuse for the main fleet to have been so catastrophically distant as to be incapable of a timely defense. Even if there somehow was a big enough distraction necessitating a massive military response, surely Xandar would have retained a large 'Home Guard', to say nothing of fortifications such as orbital guns, minefields, sensor disruption fields, barriers etc.? How could such an advanced civilisation neglect the most basic principles of national/planetary security?
If those factors were in play, even approaching the planet would have been a suicidal proposition for the Accuser, with or without an Infinity Stone. Commanding just one Capital ship and the fighters on it, he had barely enough manpower for even a brief skirmish. It would be like a single battleship challenging the US Navy; any kind of engagement would shut up the mouse that roared once and for all.