Klaus has no interest in ruling the world, in fact he HATES being in charge. He laments that he would like nothing more than to just do his research in peace but he cant. Europa fell apart while he was gone, and he felt responsible for fixing it. So he did, his way. And it more or less worked. He calmed europa down big time. He kept a tight lid on incipient war and if he had a few more years to establish his son it might have even worked past his direct rule. Im sure there would have been unrest either way, but it would have likely been smaller as gil would already be handling most of it before the official turnover and so be a known quantity not to be messed with.