English: Over the span of more than six decades, the U-2 evolved from a relatively basic, high-altitude camera platform for performing clandestine reconnaissance missions into a complex, multisensor platform that has been adapted for a multitude of civil and military roles. Variants in more than a dozen configurations have been used for intelligence gathering, strategic and tactical reconnaissance, communications relay, battle-damage assessment, treaty monitoring and verification, disaster relief, environmental and Earth resources studies, and a wide variety of scientific research. Born of a Cold War necessity to maintain the balance of power between East and West, the U-2 now serves equally well as a high-altitude tool for tracking terrorists in the mountains of Afghanistan or for tracking the migration of destructive spruce bark beetles through the forests of Alaska.