The Pentagon learned in August 2013 — when the U.S. came close to striking Syria over the Assad regime’s use of sarin gas — that it was woefully unprepared to face chemical or biological weapons on the battlefield. Now Darpa thinks it has a solution, called the Laser UV Sources for Tactical Efficient Raman program, or LUSTER. The Defense Department’s research arm announced this week it would begin developing a small-scale, portable and budget-conscious detection system that will rely on high power and efficient ultraviolet lasers.