South Korea has bought 100 Harpy unmanned aerial attack vehicles from Israel for $52 million. Harpy is a fire-and-forget weapon. Sent in the general direction of the enemy, it can detect radar emissions and then will fly toward and attack them. Harpy carries a 32kg warhead to a range of 500km. The US Air Force wanted to use Harpys in the Kosovo War, but its warhead and range technically make it a cruise missile, which would be banned by the US-USSR treaty from the early 80s.--Stephen V Cole