Using UAVs prevents soldiers from being killed.  To put it bluntly any military or intelligence service wants to keep its own men safe while carrying out its missions; Unmanned Aerial Vehicles are the ultimate capability with which to manage this. No military or civilian personnel are going to be killed if the delivery vehicle is controlled from the United States. This means that unlike in other methods of attack the UAV can take its time even if it is at risk. In the war in Kosovo NATO air forces had to launch their attacks from 15,000 feet due to worries they would be shot down. [1] Attacking from such a height from a fast moving aeroplane makes missing the target much more likely.  [1] Thomas, Timothy, ‘Kosovo and the Current Myth of Information Superiority’, Parameters, Spring 2000, pp.13-29.