Israel has spent $250 million building a high-tech border fence in Gaza, aimed at keeping Palestinian terrorists out of the country. It includes remote control machine guns, robotic jeeps, and electronic sensors, along with barbed wire and trenches. It's been described as one of the most formidable barriers in the world, though there are ways around it, including rockets and tunnels. The army says that with the evacuation of 21 Gaza settlements, it needs just half the manpower to secure Gaza--five battalions instead of 10.