Conquest as a purely military endeavour is not the best way to think about it - after all the people being conquered are going to be doing most of the dying. B

Conquest as a purely military endeavour is not the best way to think about it - after all the people being conquered are going to be doing most of the dying. Being part of the Roman Empire probably offered many advantages - certainly being a Citizen had numerous advantages, http://en.wikipedia.org/wiki/Roman_citizenship http://en.wikipedia.org/wiki/Roman_citizenship. Similarly being part of the British Empire presumably also had advantages. So the real work of establishing decentralized imperial republics is going to be in the social and adminstrative functions applied after the dust of conquest has settled. This approach seems to the one followed in Iraq and Afghanistan but the Western powers do not seem to be quite so competent as the Romans.