Peter Singer was quoted in an article by the Economist about military drones:
In recent years drones have become a vital component of air power. America’s armed forces have a fleet of more than 11,000 drones, compared with just a handful in 2001. Peter Singer of the New America Foundation, a think-tank, says around 80 countries now have military drones, including about 20 with armed ones, either already in use or in development. But the vast majority are unarmed surveillance aircraft of various shapes and sizes.