CARLISLE, Pa. — Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, pleaded with defense contractors to “go faster” as fears grow that the country’s stockpile of weapons is dangerously low after a series of attacks on Iran. “What I need you to know — and I know this is simple for me to say but hard to do — but go faster, please, go faster, think bolder,” he told the Pennsylvania Defense and Innovation Summit. “We all need to deliver quality weapons, delivered on time with shortage of lead times and lower costs,” he said. US Chairman...