Similarly, some drones are used only for intelligence-gathering, some are used for lethal action, and some are used for both. The Global Hawk shot down by Iran was purely an intelligence asset. Think of it as the remotely piloted equivalent of a U-2 spy plane, whose sole purpose is collecting intelligence so that policy makers have a more accurate understanding of events on the ground. The Global Hawk is expensive, costing more than $100 million each. It has no ability to strike targets, and its only real defense is altitude. Its job, quite literally, is to stay above the fray-flying at 65,000 feet or higher to avoid enemy air defenses and staying aloft for more than 30 hours at a time to gather imagery and signals intelligence. Sending a Global Hawk is not a particularly provocative act, but shooting one down is more so, precisely because it poses no threat to human life. So why did Iran do it? Most likely Tehran was trying to send some nuanced signals, dialing tensions up just a notch but not too much, and letting American leaders know that Iran has better air defenses than they probably assumed.
Other drones are designed primarily or exclusively for lethal action. The Islamic State made low-tech lethal drones by purchasing rudimentary quadcopter hobbyist drones off the internet and strapping explosives onto them. ISIS flew so many of these buzzing quadcopter drone-bombs during the battle of Mosul that one American commander likened them to killer bees. American troops have a drone called the Switchblade, which fits into a backpack, weighs less than six pounds, can fly for just 10 minutes and 10 kilometers. It’s designed to be used in the field like a smart, longer-range hand grenade. Using or losing a Switchblade is unlikely to lead to states spiraling into conflict. If the Switchblades are coming out, chances are conflict has already arrived.
Then there are Predators and Reapers, which are used against suspected terrorists in Afghanistan, Yemen, and elsewhere. They combine persistent stare and precision strike. These drones can loiter over targets for hours, days, even weeks, closely monitoring developments and collecting intelligence-and then fire missiles when the time is right, with the push of a button. Importantly, these drones are nearly entirely defenseless, flying low and slow. With propeller motors, they’ve been likened to flying lawn mowers. That’s why they operate in uncontested air environments. Against a nation with reasonably good air defenses, Predators and Reapers don’t get far or achieve much. The risk of crisis escalation is somewhat higher with these drones because they inherently have two uses; from the enemy’s point of view, it’s impossible to know whether a Reaper or Predator is simply conducting surveillance or is about to strike. And where there’s uncertainty and ambiguity, miscalculation is more likely.