If the answer is " no " , we might , instead , fall prey to what prof morris calls the " five horsemen of the apocalypse " climate change , famine , state failure , migration and disease .
Taking his cue from the " four horsemen " , mr blair emphasised that global zero had to advocate the kind of pragmatic actions that mainstream politicians and foreign-policy experts could endorse , while preserving , as a destination , a goal that seemed inspiring .