The USS Greeneville, a massive nuclear submarine, accidently rammed and sank the Ehime Maru, a Japanese fisheries training vessel, off Hawaii on Feb. 9, 2001, killing nine. This week, nearly two years later, the Greeneville's former captain, retired Cmdr. Scott Waddle, traveled to Japan to apologize in person to the survivors and the bereaved families.

Some family members and a vocal minority whose views have been widely reported overseas wondered this week why Mr. Waddle waited so long. It is a fair question, but there are reasonable answers. On balance, his visit -- which obviously took a great deal of courage -- was both welcome and necessary. It should help heal wounds sustained by everyone involved in this painful affair: the survivors, the victims' families, Mr. Waddle and his family and the U.S. and Japanese governments, whose ties were strained by the incident.

This is how it should be. The sinking of the Ehime Maru was, after all, an accident. A result of gross negligence, certainly -- for which Mr. Waddle was stripped of his command and formally reprimanded by a U.S. military court of inquiry -- but an accident nonetheless, not an act of malice or hostility. Furthermore, it is obvious from everything Mr. Waddle has said and done since the day of the sinking that the experience has been nothing less than traumatic for him. His words both before and during this week's emotional visit leave no room to doubt the sincerity of his remorse.