Picture it. Around 3,400 years ago, the Israelites entered Canaan, the promised land. The city of Jericho was a problem for the Israelites. Prior to Israel's entry into Canaan, Jericho's population had prospered, more or less, for about 4,000 years, protected by a fortified wall. It was state of the art when it came to defenses. In order to take Canaan, the Israelites needed to destroy its occupants, starting with Jericho. They marched around the city' walls for seven days carrying the Ark of the Covenant -- the same one that melted the Nazis in that movie -- and then blew trumpets and shouted, which knocked the walls down. Then they rushed into the city and killed every man, woman, child and animal, except for the prostitute Rahab, whom they saved. According to the Bible, Rahab still lives in Israel today. If you ask her, she'll tell you that a wall is the way to go. The moral of the story is that after you build a wall, you have to budget additional money for repairs. You can't ignore it for 4,000 years and expect it to hold.
What if we had walls on wheels?
