“For the better part of three decades, and certainly from the Carter presidency to the present day, the operating assumption has been that Republicans are strong on defence, Democrats not so much. … Mr Kerry may be able to flip the ‘strong on defence’ stereotype and fully reclaim it for the Democrats for the first time since the Truman era.” – Philip James in the Guardian
Much as hesitate to disagree with a “former senior Democratic party strategist,” I think it’s unlikely that people thought the Democrats were stronger on defense because they talked more about it, or promised better results. The Democrats were considered strong on national security because they built more weapons (and started more wars). (JFK became President partly because he was able to convince voters that a (non-existent) “missile gap” existed between the United States and the Soviet Union. Truman, also, is the only person to have ever authorised the use of nuclear weapons.) So I think it’s a mistake to think that Kerry can persuade the public that he is strong on defence without promising to flash some force (i.e. “hard” power) if the need arose. (Perhaps unfortunately.)