What Alpheo meant, though cloaked in the silk of contempt and delivered like a man swatting flies from his wine, was that while certainly possible to put an end to the war completely through military means, it wasn't in his immediaty interest, as it was simply too bothersome.
Yes, it was bothersome , but only in the way cleaning up after a feast is bothersome.
The heavy lifting had already been done—the armies crushed, the rebellion's back snapped like a dry twig beneath a boot—but a few pieces remained on the board: stubborn, proud pieces holed up in high towers and stone keeps. If he truly wished to erase the last embers of resistance, all it would take was time, patience, and blood.