Military lasers are the latest evolution in "not getting killed" technology. Defense and offense in war tend to be cyclical--for a while, weapons are very good getting through to their targets, but then someone invents better armor, which works until a new weapon is made. Since the advent of gunpowder, really, offensive weapons have outmatched defenses. It's simply easier and cheaper to fire many relatively inexpensive explosives at a target than it is to fire pricey guided missiles to stop attacks in midair. Israel's Iron Dome system, probably the best known missile-intercepting system right now, regularly fires $40,000 missiles to stop $1,000 rockets.