U.S. Sen. John Kerry, the Democratic nominee for president, is now officially embarked on what promises to be a close race for the White House. He made a good start at the party's national convention in Boston last week by pledging to restore "trust and credibility" to the presidency and rebuild Western alliances split by the Iraq war. He faces two major challenges in the runup to the Nov. 2 election: One is to sustain his newfound image of strength; the other is to explain his policy goals more clearly.

Mr. Kerry had suffered an image problem -- a persistent perception that he was soft on defense and security -- ever since he declared his candidacy. That problem appears to have evaporated at one of the most united Democratic conventions in decades. In a symbolic gesture to portray himself as a tough leader, but one who will "never mislead us into war," he gave a crisp military salute on stage, saying, "I'm reporting for duty."

Indeed, symbolism is the stuff of a presidential nominating convention, Democratic or Republican. So it was with the four-day gala in Boston, which was elaborately stage-managed by "spin doctors" to sell Mr. Kerry as a decorated Vietnam hero. A dozen of Mr. Kerry's crew mates in Vietnam pitched in, among them a Special Forces officer whose life Mr. Kerry saved in 1969 as commander of a navy boat.