In 2007 Israel began deploying remote-operated sentry guns along the border fence separating it from the Gaza Strip. That same year South Korea announced it had plans to install sentry guns along the Demilitarized Zone (DMZ), the no-man’s-land dividing it from North Korea. Those plans were delayed for a few years, but North Korea did begin using sentry guns along the DMZ in 2010. The use of these remote-operated weapons systems has stirred some controversy, and it’s also proved to be lethally effective.