that know what discretion tries to cover. Pakistani officials, the former CIA station chief in Islamabad and scholars all over have repeatedly argued that local governments in these countries are crippled by the taint of tolerating the American drone presence. Drone strikes weaken forces of stability while stoking the anger that fuels terrorist movements. It hardly matters from a political point of view whether drones avoid civilian casualties; the secrecy around them, the historical memory of these societies and the impossibility of clearly identifying 'bad guys' in them together mean that the programme will continue to misfire. Drones have succeeded beyond the British Air Ministry of the 1920s in making possible a truly discreet pursuit of war and empire abroad. More worrying than the pilot's new remoteness is the near-total remoteness of the American public that it underwrites. If that public can ever be awoken, it will face a grim comparison. In the 1920s, British officials gamely embraced 'terror' as their aerial regime's real tactical principle. Today's dynamic closely resembles that of the British era: a frightened population living under constant threat from a distant - now even more distant - enemy. Drone enthusiasts openly praise the uneasiness produced by drones' 'persistent stare capability' and news reports testify to civilians' fear of the drones. But are Americans ready to accept that they have embraced terror too? Priya Satia is associate professor of history at Stanford University, in the United States The future of global warfare: killer robots Pre-emptive prohibition on