DDG(X) and the variable meaning of high-low mix

The projected DDG(X) is larger and roomier than the Ticonderogas it is intended to replace, despite carrying a destroyer designation. In this interpretation, that growth acknowledges that the cruiser mission needs more development margin than the Spruance-derived hull provided. The familiar high-low mix is only shorthand because both ends change with the threat. An offshore patrol vessel may supply numbers in a permissive environment, whereas even the low end of a high-threat fleet may need to be a frigate. A frigate can be the high-capability unit in a quiet setting but cannot substitute for a much more powerful escort where the threat is intense.