The Stainless Steel Rat Gets Drafted - Harry Harrison

Jim was left in the custody of the League Navy, this story opens with him escaping from his prison cell on the League base on Steren-Gwandra, where he is awaiting deportation back to his home world. He has discovered that Bibs, a crew girl from Captain Garth's ship, is also a prisoner. Jim holds Garth responsible for the Bishop's death, and plans to hunt him down, with Bibs' help. Garth is really the crazed Captain Zennor, head of an army which continually defies League peace treaties, and now plans to invade and conquer the planet Chojecki. The people of Chojecki are pacifists, having no armies and no police. But Garth's generals decide to attack anyway, since there are no medals for "generals who bring back the troops intact." Jim must save the people of Chojecki before he can face Garth