The Defense Department is making public the centerpiece of a new rapid-acquisition system -- developed in secret over nearly four years -- that aims to convert existing combat capabilities into "strategic surprises" for near-peer competitors in hopes of attracting new ideas from across the U.S. military and private sector, while simultaneously bolstering conventional deterrence against China and Russia. The Strategic Capabilities Office, a Pentagon shop formed in 2012 whose work until recently has largely been kept under wraps, has revealed...