NEW YORK -- The vice chairman of the Joint Chiefs of Staff said this week that Defense Department leaders are actively exploring options for eliminating the short-takeoff-and-vertical-landing variant of the Joint Strike Fighter by examining whether an alternative mix of tactics, doctrine and other weapons systems might address requirements the F-35B is designed to meet. The comments of Gen. James Cartwright, made on Dec. 2 to an audience of Wall Street investors here, suggest Defense Department leaders are considering following...