Why shouldn't he talk about national security when that's the hot topic for an incoming president.
Kerry served in real combat.
Bush got into the national gaurd flying a plane that was being removed from service, i.e. there was 0% chance that he was going to have to go to Vietnam, and it's questionable if he even showed up for duty...sure he might have shown up to have his teeth cleaned for free.
Cheney got a deferment from service...fucking wimp
I can't think of one member of the current administration other than Collin Powell who's actually served in the military.
Face it the republican administration is a bunch of wimps when it comes to putting your money where your mouth is.
BTW you wimpy republicans.