Some 10,000 people took advantage of sunny weather last week to attend the town of Lisburn's annual "fun run." The final race, a 13-mile half marathon, had just ended, and the assembled throng was beginning to disperse. Suddenly the peaceful scene was shattered by an explosion that turned a blue van slowing for a traffic light into a fireball. All six passengers, British soldiers who had participated in the races, were killed. The only wonder was that there were no fatalities among onlookers, though eight of them were injured.
Responsibility was quickly claimed by the outlawed Irish Republican Army. It was...