"Curiously Civilised War"

John Keegan argues that World War I was "a curiously civilised war" because no major material damage was done. No major cities were wiped out, and for the most part civilian land was left alone. I don't totally agree with Keegan's statement however, because so many human lives were lost. Keegan himself says that World War I "damaged civilization."  I'm not quite sure any war can be labeled as civilised... it seems to me civilised war is an oxymoron. Diplomacy, although it doesn't always 'work,' would be more fitting under the category of "civilised."