The naval base at La Spezia in northern Italy is in an advanced state of decay. The grand Mussolini-era barracks are shuttered; the weeds won their battle with the concrete some time ago. But amid the crumbling masonry, there is an incongruously neat little building, shaded behind a line of flags, with smartly outfitted security men behind its glass doors. This is Nato’s Centre for Maritime Research and Experimentation (CMRE). As one battleship after another has been removed from what remains of the Italian navy, and the base is wound down, the centre is preparing for a new kind of marine warfare amid the wreckage of the old.