War and Peace, and Politics
News analysis on dealing with terrorist alerts in heat of tight presidential campaign; points out that while Sec Tom Ridge dismisses link between latest warning and campaign, he also credited Pres Bush's 'leadership in the war against terror' with gathering information; rival John Kerry may not share that view, but biggest thing Democrats may have to fear this campaign is power of fear itself, as polls show that Bush's handling of terrorism remains his only clear advantage over Kerry in razor-close race; Bush would not be politically canny not to remind public of his strong suit, which is why his convention is in New York, why he has new ads with images of firefighters and the flag, and why he discusses terrorism with gravitas of White House Rose Garden setting; Bush at same time must take pains not to let political tail wag terrorism dog: use of old intelligence leaves even some in law enforcement wondering why Ridge raised alarm just now (M)